JPS6321911A - Production of ultrathin fiber bundle - Google Patents

Abstract

PURPOSE:To obtain an ultrathin fiber bundle having little point bonding and entanglements, by blending a thermoplastic resin with water and an auxiliary in a molten state and passing the blend through a throttle orifice between the screw outlet of an extruder and the die. CONSTITUTION:A fibrous material formed in melting and blending in an extruder is passed through at least one throttle orifice 10 set between a screw outlet 1a and a die 2. Ultrafine fibers bonded at points and entangled are mutually separated, orientated in a fixed direction, put in order and a fiber bundle of a great number of ultrathin fibers having <=200mu diameters collected approximately in a parallel state is extruded from the die 2.

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for producing an ultrafine fiber bundle in which an ultrafine fiber bundle is already obtained at this stage by spinning from a spinneret (die).
In particular, it relates to a method for producing ultrafine fiber bundles that can be easily removed. [Prior Art] The applicant of the present application previously filed a patent application dated September 25, 1980, Japanese Patent Application No. 198669, in which a heat exchanger with a substantially circular cross-sectional shape and a substantially indefinite length of 200 μm or less in diameter was proposed. A large number of plastic arborescent ultrafine fibers are bundled in a substantially parallel state, and the ultrafine fibers that make up the fiber bundle are partially adhered to each other. We proposed a characteristic ultrafine fiber bundle and its manufacturing method. The method for producing ultrafine fiber bundles at the time of this application involves melting and kneading a thermoplastic resin, water, and an auxiliary agent that assists in dispersing the water in the thermoplastic resin in a screw extruder. Focusing on the fact that the fibers are naturally formed into fiber bundles in the extruder during melting and kneading, we created fibers with a diameter of 200 mm from one orifice hole after melting and kneading in the screw extruder.
This method is characterized in that a large number of ultrafine fibers of μ or less are gathered in a substantially parallel state and a r-shaped fiber bundle is spun. This method of manufacturing ultrafine fiber bundles involves extruding a molten polymer from an extruder and then drawing and spinning it, whereas the conventional manufacturing method involves extruding a molten polymer from an extruder and then drawing and spinning it.In contrast, the method for manufacturing ultrafine fiber bundles is that the fiber bundles are already formed into ultrafine fiber bundles in the extruder and then spun. This is an epoch-making method that cannot be compared to conventional spinning methods. [Problems to be solved by the invention] However, in the method proposed in the previous application, the single fibers constituting the fiber bundle are point-adhered or intertwined with each other in a considerable portion, resulting in a spun microfiber bundle. Even if you try to defibrate it afterwards, it will be difficult to defibrate it. In the production of the ultrafine fiber bundle, the present invention allows the ultrafine fibers to be point-adhered or intertwined with each other and to be oriented before being extruded from a die. The technical problem is to be able to obtain ultrafine fiber bundles and to facilitate the fibrillation of ultrafine fiber bundles after production. [Means for Solving the Problems] In order to solve the above-mentioned technical problem, the present invention provides a method of fabricating a large number of ultrafine thermoplastic resin fibers having a substantially circular cross-sectional shape, substantially indefinite length, and a straight weight of 200μ or less, or substantially parallel fibers. In the method for manufacturing ultrafine fiber bundles that are tightly bundled, the following technical measures were taken. That is, in the present invention, after melting and kneading a thermoplastic resin, water, and an auxiliary agent for assisting the dispersion of water in the thermoplastic resin in a screw extruder, the process of melting and kneading the thermoplastic resin, water, and an auxiliary agent for assisting the dispersion of water in the thermoplastic resin, and then By passing the formed fibrous material through at least one restricting orifice 10 provided between the screw outlet 1a and the die 2, a large number of ultrafine fibers with a diameter of 200 μ or less were converged in a substantially parallel state. The fiber bundle is extruded from the die 2 at the tip of the extruder, and the most distinctive feature is that the fiber bundles formed by melting and kneading are passed through the squeezing orifice 10, where they are bonded at points and intertwined. The purpose is to separate the ultrafine fibers and orient them in a certain direction. [Function] The thermoplastic resin, auxiliary agent, water, manufacturing equipment, etc. according to the present invention will be described below, and then the specific manufacturing process will be explained. Thermoplastic resin> The thermoplastic resin used in the production of the ultrafine fiber bundle according to the present invention may be any water-insoluble resin that can be made into fibers, regardless of whether it is crystalline or non-crystalline. Density polyethylene, medium and low pressure group low density polyethylene, high density polyethylene, ultra high molecular weight polyethylene, polypropylene, ultra high molecular weight polypropylene, poly 1-butene, poly 3
-Methyl-1-butene, poly4-methyl-1-pentene or ethylene, propylene, -butene, 3-methyl-1-butene, l-pentene, 4-methyl-1-pentene, l-hexene, 1- Random or block copolymers of α-olefins such as decene, copolymers of α-olefins and conjugated or non-conjugated dienes such as ethylene/butadiene copolymers, ethylene/ethylidene norbornene copolymers, ethylene/propylene/ Copolymers of two or more α-olefins and conjugated or non-conjugated dienes, such as butadiene ternary copolymers, ethylene/propylene/synchropentadiene ternary copolymers, ethylene/propylene/ethylidene norbornene ternary copolymers, etc. , ethylene/acrylic acid copolymer, ethylene/vinyl acetate copolymer, ethylene/
Vinyl alcohol copolymers, ethylene/vinyl compound copolymers such as ethylene/vinyl chloride copolymers, polystyrene, acrylonitrile/butadiene/styrene copolymers, methyl methacrylate/styrene copolymers, α-methylstyrene/styrene Styrenic resins such as copolymers, polyvinyl chloride, polyvinylidene chloride, vinyl chloride/vinylidene chloride copolymers, vinyl copolymers such as polymethyl acrylate, polymethyl methacrylate, nylon 6, nylon 66, nylon 610, nylon 11, nylon 1
Examples include polyamides such as No. 2 polyamides, thermoplastic polyesters such as polybutylene ethylene leftate, polybutylene ethylene lefttate, polycarbonate, polyphenylene oxide, polysulfone, polyphenylene sulfide, polyether ether ketone, etc., or mixtures thereof. Among these, low-density polyethylene and ultra-high molecular weight polyethylene, which have conventionally been difficult to convert into ultra-VFI fibers, can also be used in the same way as the resin. Auxiliary agent> The auxiliary agent used in the production of the ultrafine fiber bundle according to the present invention is such that when the thermoplastic resin and water are kneaded, the water gradually becomes thermoplastic! Its main function is to disperse the thermoplastic resin into the fingers to cause phase inversion, resulting in the production of an aqueous dispersion in which the continuous phase is water, in which the thermoplastic resin is dispersed in water. It is believed that the occurrence of such a phenomenon by spacing kneading is the reason why ultrafine fiber bundles are produced all at once. In other words, it is not possible to produce ultrafine fiber bundles simply by mixing a thermoplastic resin and water without using an auxiliary agent.
Therefore, the object of the invention cannot be achieved. The general concept of an auxiliary agent that exhibits this type of action is that it has both a hydrophilic group and a lipophilic group in its molecule, and more specifically, it consists of the following compounds alone or in combination of two or more of them. used. (A) Water-swellable or water-soluble thermoplastic resin (B)
Water-soluble or water-insoluble thermoplastic resin modified with unsaturated carboxylic acids (C) Surfactant (used in combination with A and/or B) (D) Organic solvent (used in combination with A and/or B) (E) Others (used in combination with A and/or B) (A) Water-swellable or water-soluble thermoplastic resin that swells or dissolves in water (infinite swelling) , polyvinyl alcohol, methyl cellulose, carboxyl methyl cellulose or its sodium salt, polyacrylic acid, sodium polyacrylate, polyacrylic acid amide, and the like. Among these, polyvinyl alcohol, especially saponification degree 65
~98% or even 80-97% partially saponified polyvinyl alcohol is advantageous. When these auxiliary agents are kneaded together with the aforementioned thermoplastic resin and water, the auxiliary agents are first uniformly kneaded into the thermoplastic resin, and then the auxiliary agents are swollen by the water and the thermoplastic resin is divided. Then, water penetrates further into the interior, swelling the auxiliary agent present inside and promoting the fragmentation of the thermoplastic resin, ultimately giving an aqueous dispersion that looks like thinly fragmented thermoplastic fingers. it is conceivable that. The features of this type of auxiliary agent are: (1) There are fewer types of applicable thermoplastic 1 fingers compared to the auxiliary agents described below; (2) If the manufactured ultrafine fiber bundle is left undisturbed, time will pass. As the process progresses, the fiber bundle becomes as if the ultrafine fibers are firmly bonded to each other, and as the result, the fiber bundle becomes more hydrophilic. These are those obtained by graft copolymerization or block copolymerization of unsaturated carboxylic acids with poorly water-soluble or water-insoluble resins, or random copolymerization during IHI, and have particularly good compatibility with thermoplastic resins used as fiber raw materials. Furthermore, those having a small distal viscosity are preferable. The resin solubility parameter (Sp value) is a guideline for compatibility, and the difference in Sp value is 2 (Cat/cz3)V'
It is preferably within 1 (Ca 1/am")". The Sp value is the cohesive energy density
It is a value defined as a 17゛ squared value, and the contribution value Vi of the Kyoko group to the molar volume and the cohesive energy En of the atomic group are
D., W., Van, Klevelen”Pro
parts of Polymers'' (E 1s
It can be determined by calculating from the formula using the values described in J. Evier, 1972). An example of a material with a small dispersion viscosity is a wax-like material with a small molecular weight. Although this modified resin is hydrophilic because it has carboxy groups derived from unsaturated carboxylic acids or derivative groups thereof, it does not swell in water because the base resin is poorly or insoluble in water. . Further, the unsaturated carboxylic acid units in the modified resin include unsaturated carboxylic acids or esters of other substances, or neutralized or saponified units of these to form unsaturated carboxylic acid salts. Among these, it is preferable that the polymer 19 contains 0.1 to 5 mmol equivalents, particularly 0.2 to 4 mmol equivalents, of unsaturated carboxylic acid salts in terms of 10-0-groups. Modified resin is a copolymerization of the monomers constituting the poorly water-soluble or water-insoluble thermoplastic resins mentioned above and unsaturated carboxylic acids, and as unsaturated carboxylic acids (meth)
Acrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, notraconic acid, crotonic acid, isocrotonic acid, metsucic acid
,2,1)hept-5-ene-2,3-dicarboxylic acid)
, unsaturated carboxylic acids or anhydrides thereof such as maleic anhydride and notraconic anhydride, methyl of the above unsaturated carboxylic acids,
Examples include esterified products such as monostyl and diesters such as ethyl and propyl, and unsaturated carboxylic acid salts such as alkali metal salts, alkaline earth metal salts, and ammonia salts. Of course, it will be obvious to those skilled in the art that instead of copolymerizing a plurality of monomer components, the above-mentioned unsaturated carboxylic acids may be graft-polymerized or block-polymerized to a thermoplastic resin, such as an olefin resin. As mentioned above, a preferred embodiment of the modified resin is one in which 1 g of the polymer contains 0.1 to 5 mmole equivalent of unsaturated carboxylic acid salt in terms of -C-〇- group; To produce a thermoplastic resin that has been modified in advance with an unsaturated carboxylic acid, its anhydride, or its ester, a basic substance, that is, a substance that acts as a base in water such as alkali metals, alkaline earth metals, ammonia, and amines, is used. , alkali metal oxides, hydroxides, weak acid salts, hydrides, alkaline earth metal oxides, hydroxides, weak acid salts, hydrides, alkoxides of these metals, etc. I can give an example. Specific examples of such basic substances are shown below. ■ Alkali metals include sodium, potassium, alkaline earth metals include calcium, strontium, barium, and amines include inorganic amines such as hydroxylamine and hydrazine, methylamine, ethylamine, ethanolamine, and cyclohexylamine. ,■ Oxides, hydroxides, and hydrides of alkali metals and alkaline earth metals include sodium oxide, sodium peroxide, potassium oxide, potassium peroxide, calcium oxide, strontium oxide,
Barium oxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, sodium hydride, potassium hydride, calcium hydride, ■ Weak acid salts of alkali metals and alkaline earth metals include carbonic acid. Sodium, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, calcium hydrogen carbonate, sodium acetate, potassium acetate, calcium acetate, ■ Compounds of ammonia and amines include, for example, ammonium hydroxide, resorbed ammonium compounds, such as tetramethylammonium hydroxide. , hydranone hydrate, etc. As the carboxylic acid group or carboxylic acid ester group that has been neutralized or saponified with a basic substance, alkali metal carboxylates such as sodium carboxylate and potassium carboxylate, and ammonium carboxylate are preferable. preferable. (C) Surfactant A surfactant is not used alone as an auxiliary agent, but is used in combination with A and/or B above. The surfactant used may be an anionic surfactant, a cationic surfactant, a nonionic surfactant, or a zwitterionic surfactant, but in particular, anionic surfactants and nonionic surfactants may be used in combination with the above A and/or In combination with B, it is possible to produce ultrafine fibers with a diameter of 100μ or less, approximately less than f250μ, which is preferable. Here, as anionic surfactants, in addition to those that are in the form of anionic surfactants from the beginning,
It also includes organic compounds that react with the basic substances listed in ~■ to ultimately become anionic surfactants. In other words, it is better to melt-knead the thermoplastic resin, A and/or B, and the organic compound, and then add a basic substance and continue the melt-kneading to convert the organic compound into an anionic surfactant. The resin and anionic surfactant mix well, and ultrafine fibers with a smaller diameter can be obtained. Such an organic compound may be any compound as long as it reacts with a basic substance to become an anionic surfactant, and preferred examples include first-class higher fatty acids, second-class higher fatty acids,
1st treatment higher alcohol sulfuric ester, 2nd handling higher alcohol sulfuric ester, 1st handling higher alkyl sulfonic acid, 2nd handling higher alkyl sulfonic acid, higher alkyl disulfonic acid, sulfonated higher fatty acid, higher fatty acid sulfuric ester,
Higher fatty acid ester sulfonic acid, higher alcohol ether sulfuric acid ester, higher alkyl ether sulfonic acid, alkylolated sulfuric acid ester of higher fatty acid amide, alkylbenzene sulfonic acid, alkylphenol sulfonic acid, alkylnaphthalene sulfonic acid, alkylhenshiimidazole sulfonic acid, etc. can be exemplified. Among these, particularly preferred are higher fatty acids, particularly saturated or unsaturated higher fatty acids having 10 to 20 carbon atoms, more specifically capric acid, undecanoic acid, undecanoic acid,
Saturated fatty acids such as lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, and arachidic acid; unsaturated fatty acids such as lindelic acid, tuzic acid, petroselic acid, oleic acid, linoleic acid, lilunic acid, and arachidonic acid; Mixtures of these can be mentioned, with saturated fatty acids being particularly preferred. Specific examples of surfactants include anionic surfactants and nonionic surfactants. salt, second-class higher alcohol sulfate ester salt, first-class high-class alkyl sulfonate, second-class high-class alkyl sulfonate, higher alkyl disulfonate, sulfonated high-class fatty acid salt, higher fatty acid ester sulfonate , sulfate salts of higher alcohol ethers, sulfonate salts of higher alcohol ethers, alkylolated sulfate salts of higher fatty acid amides, alkylbenzene sulfonates, alkylphenol sulfonates, alkylnaphthalene sulfonates, alkylbenzimidazole sulfonates etc., the latter are alkyl ethers, alkyl allyl ethers, alkyl thioethers, alkyl esters, sorbitan monoalkyl esters, polyoxine ethylene alkyl amines, polyoquinoethylene alkylamides, polyoquine ethylene borioquine pyrene,
pentaerythritol ester, saccharose ester,
Examples include fatty acid ethanolamide, methylolamide, oquinemethylethanolamide, and the like. Of course, anionic and nonionic surfactants other than those exemplified, as well as cationic surfactants and amphoteric ionic surfactants not exemplified here, may be used.More detailed examples of these surfactants can be found, for example, in Horiguchi. It is disclosed in "Synthetic Surfactants" by Hiroshi (1968, Sankyo Publishing 1st edition). Among the above surfactants, if one converted into an anionic surfactant by processing a basic substance is used, the produced ultrafine fiber bundle exhibits properties on the alkaline side, that is, with a pH of 9 or more. In addition, nonionic surfactants produce ultrafine fiber bundles that exhibit approximately neutral pH. In the case of nonionic surfactants, those with an HLB value of 13 to 19 are preferred because they produce ultrafine fibers with a smaller diameter. HLB value is Griffin
It is derived from the formula of n, and the details are given in Surfactant Handbook (written by Nishiichi Ike, Sangyo Tosho, 1972), 307-31.
It is disclosed on page 0. (D) Organic Solvent The organic solvent has a high molecular weight or a narrow molecular weight distribution and a high spacing viscosity, and is used when forming ultrafine fiber bundles from thermoplastic resins that are difficult to spacing knead. Therefore, melt fluorate (MFR)
, ASTM DI 238) l 9/10m
The effect is remarkable when applied to digits of less than 1n, but of course, when applied to digits with a small viscosity, that is, V F R is 19
It can also be applied to resins of /lomin or higher. Furthermore, the enumerated solvent is not used alone, but in the above-mentioned A and/or B.
Furthermore, it is used together with C as necessary. Examples of such organic solvents include aromatic hydrocarbons such as benzene, toluene, xylene, styrene, α-methylstyrene, and vinylbenzene, aliphatic hydrocarbons such as hexane and heptane, and halogenated hydrocarbons such as trichloroethylene. be. (E) In addition, petroleum resins, ronone, asphalt, etc. may be used in combination with A and/or B, as necessary, in addition to C and D in the ponds listed above in A-D, and water swelling of the middle terrarium A. Alternatively, it is preferable to combine it with a water-soluble resin. <Preferred embodiment of auxiliary agent> There are various ways of using the auxiliary agent for deafness, for example, use of A or B alone, combination of A and B, combination of A and/or B and C, combination of A and/or B and D. Examples include a combination, a combination of A and/or B, C and D, and a combination of A and E. More preferably, when making the diameter relatively thick (approximately 50 μ or more), use neutralized or saponified modified tree 11W (B), or use neutralized or saponified when making it thin (approximately less than 50 μ). When aiming at neutral ultrafine fibers, a nonionic surfactant may be selected as (C) from the above combination, or a modified resin (B) and a surfactant (C) may be used. When aiming at ultra-fine fibers of large resins, neutralized or saponified modified resin (B), surfactant (C) and organic solvent (D) are used, and when the fiber bundle itself is to be solidified, it is necessary to use A water-soluble resin (A) may be used. The amount of the auxiliary agent to be used varies depending on the type of thermoplastic resin to be made into ultrafine fiber bundles and the type of auxiliary agent, but it is generally 75 to 98 parts by weight of the thermoplastic resin (80 to 95 parts by weight and 2 parts by weight of the auxiliary agent). ~25 parts by weight, particularly 5 to 20 parts by weight (however, the total of both is 100 parts by weight).A particularly preferred embodiment of the present invention uses a thermoplastic resin, a neutralized or saponified modified resin, and a surfactant. 75 to 9 in each case
8 parts by weight, 1 to 20 parts by weight, 1 to 5 parts by weight (total is 10 parts by weight)
It is 0 parts by weight. ), especially 80 to 95 parts by weight, 3 to 1
6 parts by weight and 2 to 4 parts by weight. Further, in this combination, when a water-swellable or water-soluble thermoplastic resin is used instead of the surfactant, the ratio may be approximately the same as above. <Addition of water> The amount of water added to the system consisting of the thermoplastic resin and the auxiliary agent is 3 to 3 parts by weight per 100 parts by weight of the thermoplastic resin and the auxiliary agent.
40 parts by weight, especially 10 to 30 parts by weight. By keeping the amount of water within this range, the desired thermoplastic resin can be made into ultrafine fiber bundles. There are various methods of adding water, including a method in which water is added in advance to the spacing kneading surface together with the thermoplastic resin and an auxiliary agent, and a method in which water is added gradually during spacing kneading. Further, the water to be added is not only added as pure water, but also, for example, when a surfactant is used as an auxiliary agent, there is a method of adding it as an aqueous solution and adding the surfactant and water together. <Apparatus used in the present invention>

[Extruder]

The extruder used in the present invention is used for producing ultrafine fiber bundles as described below.
For the reasons described in section 1, it is desirable to use a single-screw extruder 1 that does not apply shearing force in a direction parallel to the extrusion direction of the molten resin, as shown in FIG. As for the screw shape, an intermediate mixing type screw is preferably used. A pump 4 for pressurizing water into the middle of the extruder, for example, just before the intermediate mixing section, is used as a pump 4, such as a high-pressure blunt pump.
Connect the pump. Water injection is medium. It is also possible to inject the resin in stages, not only to the straight section of the wholesaler joint section, but also to the resin loading section, immediately after the intermediate mixing section, the shearing/long wire section, the measuring section, etc.

【Thailand】

As the die 2 of the extruder 1, a porous member such as a menyu screen may be used in place of a conventional spinneret pond equipped with a single or multiple orifices 3. Furthermore, it is also possible to use a T-die or a thermal modular die. The diameter of the orifice when using the upper die 2 shown in Fig. 1 and Fig. 4 (a) and (b) is 01 to 0.
311φ, preferably 0.3 to 15Iπφ.

[Aperture orifice]

A throttle orifice 10 is formed between the screw outlet 1a of the extruder 1 and the orifice 3 of the die 2, and the melt-kneaded material passes through the throttle orifice 10. The restricting orifice 10 may have any shape as long as it can apply a certain restriction to the flow of the melt-kneaded material. The dimension thereof is preferably L/D=2 to 20, preferably L/D=5 to 12. For example, as shown in Figures 1 and 2 (a) and (b), the diameter gradually decreases from the inlet side to the center, continues to be small from the center, and gradually decreases toward the outlet. As shown in Figure 3 (a) and (b), there are cases where the diameter gradually becomes smaller or larger on the population side and the exit side, respectively, as shown in Figures 1 and 3. An example of the shape is the same as that shown in FIGS. 2(a) and 2(b), but the central portion is closed with a closing body 11, and this closing body 11 is provided with a plurality of small diameter passages 12. Further, such a restricting orifice may be provided not only at one location but also at a plurality of locations.

[Defibration device]

The fiber bundle extruded from the orifice 3 of the die 2 may be used as is, or preferably it may be defibrated to make it easier to use. As shown in FIGS. 4(a) and 4(b), the device for defibrating is provided with nozzle ports 6 on the upper and lower sides of the orifice 3, and from these nozzle ports 6, the microfiber bundle is directed from above and below. Can you give an example of something that sprays gas? In this case, the interval between the nozzle ports 6 is 0.1 to 4 my, preferably 082 to 2 m:J. The angle of the gas spray from the nozzle port 6 may be 20 to 90 degrees, preferably 40 to 80 degrees, relative to the ultrafine fiber bundle. Further, the gas to be ejected may be any gas such as nitrogen or oxygen, but air is most suitable in terms of safety and economy. The air is then jetted out from the nozzle port 6 as compressed air by an air compressor 7. In that case, the air pressure should be 1 kg/cyt'・G or more, preferably 2
There is no upper limit as long as it is at least kg7cm2・G. The air temperature may be any temperature that will cool the tip of the die and prevent the resin from clogging the tip; for example, the melting point of the resin may be ±50° C., preferably ±20° C. Note that the fiber bundles can be removed by mechanical means such as a so-called pulverizer, rather than by means of gas spraying, or by liquid means such as water jet spraying. In addition, after cutting the spun fiber bundle into a predetermined size, it is possible to obtain a crushed slurry of single fibers, which is similar to single fiber cotton, by passing it through a flocculer or crushing machine such as a pulper. You can do it. Production of ultrafine fiber bundles> To produce ultrafine fiber bundles using the above apparatus, the thermoplastic resin, auxiliary agent, and water are spacing-kneaded, and then,
The fiber is passed through a throttle orifice 10 and spun from an orifice 3 of a spinning nozzle serving as a die 2. As a result, it is possible to spin one fiber bundle in which a large number of ultrafine fibers having a diameter of 200 μm or less are gathered in a parallel state per one orifice 3. At this time, it is important to extrude under conditions in which the water is not substantially flushed, and if there are multiple orifices, a fiber bundle is formed for each orifice. Furthermore, in order to convert the resin composition to be melt-kneaded into a form in which single fibers are bundled in parallel, it is necessary to make sure that no shearing force is applied in the direction parallel to the pressing direction of the molten resin in the extruder l. It is generally necessary to perform kneading so that shearing force is applied only in two-dimensional directions other than the above-mentioned parallel directions. To explain this point, under melt mixing conditions in which shearing force is applied in three-dimensional directions, such as in melt kneading in a twin-screw extruder, water becomes a continuous phase and the melt phase becomes dispersed particles. 0
/W-type diversion is likely to occur and continuous fibrous resin cannot be obtained. This is why a single-screw extruder suitable for shearing and kneading only in two-dimensional directions is preferred as the extruder to be used in the method of the present invention. However, it goes without saying that even a multi-screw extruder can be used as long as it has been improved to be suitable for the present invention. In the dispersed state of the metallurgical material formed by the method of the present invention, the metallurgical resin has a large number of independent conventional phases oriented in the extrusion direction,
Water exists in the form of a vortex filling the interstices of these numerous phases. That is, in this dispersion type deaf, the dispersion resin becomes a dispersed phase and water becomes a continuous phase in the side plane with respect to the extrusion direction, resulting in a so-called 0/W dispersion form, but in the extrusion direction, the dispersion resin becomes a dispersed phase and water becomes a continuous phase. Both water and water are considered to be virtually continuous. In other words, the water added to the system is gradually incorporated into the thermoplastic resin by the shearing force caused by kneading and the action of the auxiliary agent, and initially water is dispersed in the thermoplastic resin (W2O
type). Furthermore, in order to continue applying the shearing force in the two-dimensional direction, the amount of dispersed water is small (at most 3 to 3 parts per 100 parts by weight of the thermoplastic resin and the auxiliary agent).
40 parts by weight), when viewed transversely to the extrusion direction, the above-mentioned dispersion form (○/W type) in which the resin is a dispersed phase and water is a continuous phase is formed. By the way, the resin is in the form of fibers with water as the boundary phase, but if it were left as it was, many of these vertebral resins would be mixed randomly, and they would be partially bonded at points,
3 Therefore, in order to pass these fibers through the throttle orifice, as shown in FIG. A large velocity gradient occurs in which the flow velocity decreases as it gets closer to the inner wall of the
Due to this difference in flow velocity, the fibrous resin phase that is partially adhered and entangled is difficult to cut and loosen, as shown in Figure 6 (a) and (b), and the direction of separation is The fibers are oriented to form fiber bundles. Then, this fiber bundle is further spun through the orifice 3 of the die 2, so that it is further oriented and the fibrous resin is aligned. In this way, the present invention differs from conventional melt spinning methods because:
Regardless of the shape of the squeezing orifice 10 or the orifice 3 of the die 2, the melted and kneaded material that passes through these orifices will be formed into a large number of ultrafine fibers (diameter of 200 μm or less) approximately in the extruding direction. The fibers come out as parallel fiber bundles. When the melt-kneaded material is finally spun to the outside, the conditions must be such that the contained water does not substantially flash, that is, the rapid extrusion that causes the water to flash as in the conventional flash spinning method should be avoided. . If the melt-kneaded material is rapidly extruded in a high fluidity state as in the flash spinning method, the water molecular film attached to the single fibers will evaporate and the single fibers will fuse together, or the water will become bubbles and cause the The fibers are incorporated into the fibers and foam, making it impossible to obtain the desired fiber bundle by rubbing. More specifically, the spinning temperature is lowered to near the melting point of the resin, the viscosity is increased within a range where the resin does not lose its fluidity, and spinning is carried out in the same manner as in ordinary plastic extrusion molding. The moisture content of the resulting fiber bundle is substantially the same as the amount of moisture present in the melt, although some moisture may evaporate during spinning. Furthermore, it is possible that the final fiber obtained by defibrating the fiber bundle has substantially no water content due to evaporation of water. Properties of synthetic fibers The spun product obtained by the method of the present invention has a large number of straight thermoplastic resin ultrafine fibers with a substantially circular cross-sectional shape and a substantially indefinite length of 200 μm or less, often 100 μm or less, twisted in a substantially parallel state. The ultra-fine fibers are bundled into a lever-shaped bundle without being tied together, and there are very few parts of the ultra-fine fibers that are partially adhered to each other, and there are also very few areas where the ultra-fine fibers are intertwined with each other. . In addition, immediately after spinning, a water molecule film exists on the surface of each single fiber. <Defibration> To explain the case where the above-mentioned gas blowing is performed by blowing air toward the ultrafine fiber bundle using a device, the fiber bundle coming out from the orifice 3 is defibrated. By blowing the fibers together, the fiber bundle is defibrated. During this defibration, the ultrafine fiber bundle before being unraveled is bonded at points among the single fibers constituting the fiber bundle due to the action of the squeezing orifice 10, and since there are very few entangled parts, unraveling is extremely easy. This can be done by 1 meter means such as a crusher, or the same can be done by means of liquid such as water spraying. By defibrating the fiber bundle, it can be defibrated into a single fiber state or an aggregate of intertwined single fibers. Also: When defibration is performed by air blowing, the water molecule film attached to the surface of each single fiber immediately after spinning evaporates, leaving the defibrated fiber aggregate in an almost dry state. Become. Uses of fibers after defibration> Fibers after defibration are used for mixing in absorbent cotton for diapers, binders for nonwoven fabrics, binders for valves for papermaking, etc. [Effects of the Invention] According to the great invention, an ultrafine fiber bundle in which a large number of thermoplastic resin ultrafine fibers having a substantially circular cross-sectional shape and a substantially indefinite length and having a diameter of 200 μm or less are bundled in a substantially parallel state is formed. It is possible to spin the microfibers in a state where there are very few parts where they are adhered or intertwined with each other. Therefore, it is extremely easy to remove the ultrafine fiber bundle, and especially,
Defibration can be easily performed by blowing gas. [Examples and Comparative Examples] <Example 1> Ultrafine fiber bundles were spun and defibrated under the following conditions. (a) Apparatus As the extruder 1, a single-screw extruder (intermediate mixing type manufactured by Yagai Tekkoji Co., Ltd.) with a diameter of 20φ and L/D=36 was used. The orifice 3 of the die 2 is, as shown in FIG. 4(b),
Diameter 0, 5. It has four yxφ arrays arranged side by side. In addition, the angle change of the nozzle port 6 is such that the upper surface inclination angle θ inside the nozzle port 6 with respect to the vertical surface of the die 2 is 40 degrees, and the lower surface inclination angle ψ inside the nozzle port 6 is 45 degrees. The compressed air discharged from the opening 6 is blown onto the ultrafine fiber bundle from the top, bottom, left and right directions at an angle of about 45 degrees. The throttle orifice 10 interposed between the screw outlet 1a and the die 2 is of the type shown in FIGS. 1 and 2, and in FIG. 2, D 1 =21. +φ, D2=2
0zxφ, D 3 = 5 x2φ, L 1
=2Ltaφ, L2=30m2φ, L3=13
There is mxφ. Also, screen mesh 5 is: 80. ＃120゜＃
200, #300, #120, ;80 are provided between the screw outlet 1a and the throttle orifice 10, and between the throttle orifice 10 and the die 2, respectively. (0) Compound ■ Low-density polyethylene (manufactured by Kochu Petrochemical Industry Ajishiki Company, product name Mirason FL-60, MFR-709/L
Omin, dense i0.9159/ca3) 96-fold iA
'lJs■ Acid-modified low molecular weight polynylene (manufactured by Kochu Petrochemical Industry Company, product name: Kochu Hiwax 2203)
A, molecular weight 2700, density f0.939/cvr3, acid g
4 parts by weight of fJ30kOHm9/9) ■Nonionic surfactant (manufactured by Kao Corporation, trade name Emulgenma 30 Polyokine Ethylene Oleyl Ether H)
LB = 16.2) 40 parts by weight of a 15% aqueous solution (c) Operating conditions ■ (1 change of each part of the machine C3... 145°C C2... 155°C C3... 155°C C4... 120°C ■Die temperature 100°C■Compressed air temperature YOQ°C■Compressed air pressure
4 kg/c7t2・G ■ Extrusion @ 1.4 to 9/Hr (d) As a result, when not defibrated, a fiber bundle with a fiber diameter of 1 to 40 μm and a substantially indefinite length was obtained. When this was defibrated by air blowing, short fibers with strength as shown in the photograph shown in FIG. 7 were obtained. The maximum length of a fiber bundle formed by intertwining one or more fibers, or a fiber bundle formed by partially bonding multiple fibers (hereinafter referred to as maximum apparent fiber length) (yolQm, i7) Example 2 The conditions were the same as in Example 1 except that the throttle orifice 10 shown in FIG. 3 was used. In FIG.
D 1 = 28: l shoulder φ, D 2 = 20z φ,
D3 = 10uφ, L 1 = 20mmφ, L 2 =
30ixφ, L3=132mφ, three small diameter passages 12 are formed, and the diameter thereof is 3:Asuφ. The results show that the fiber diameter is 1 to 40μ, as shown in the photograph in Figure 8.
m, and the maximum apparent fiber length was shorter than in Example 1, about 7+m. <Comparative Example 1> Under the same conditions as in Examples 1 and 2, when the 1° throttle orifice was not used, a fiber bundle of substantially indefinite length was obtained without removal, but since there were many point-bonded parts and entangled parts, The maximum apparent fiber length of the fibers obtained after defibration by air blowing was relatively longer than in each example, and was approximately 3Q■. The results are shown in the photograph in Figure 9.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an extruder and defibration device showing one embodiment of the present invention;
Figure 3 is a sectional view showing an example of a pond orifice;
Figures (a) and (b) are a cross-sectional view and a front view of the defibrating device part, Figure 5 is a diagram showing the resin flow in the throttle orifice, and Figure 6 (
a) (b) are fibrous inside the throttle orifice! 7 is a photograph showing the results of Example 1 after dismissal, FIG. 8 is a photograph after dismissal showing the results of Example 2, and FIG. 9 is a photograph showing the results of Comparative Example 1. This is a photograph after defibration showing. ■...Screw extruder, 2...Die, 3...Orifice, 10...Squeezing orifice. Figure 2 (a) (b) (a)
(b) Figure 4 e5 Figure 5 Figure 6 (a) (b) 72nd person Figure 9 Procedural amendment (method) 1 Indication of case Patent application No. 6519 of 1985
No. 2 No. 2 Name of the invention +5 Process for manufacturing fine fiber bundles 3 Relationship with the case of the person making the amendment Patent applicant address 3-2-5 Kasumigaseki, Chiyoda-ku, Tokyo Name (5g! Shikisha 4 Agent: Lot 7, Flower Hill, 3rd floor, 3-10 Jinbocho, Kanda, Chiyoda-ku, Tokyo Contents of amendment: Lines 7 to 1, page 36 of the specification
Figure 7 is a photograph after defibration showing the results of Example 1, Figure 8 is a photograph after dismissal showing the results of Example 2, and Figure 9 is a photograph showing the results of Comparative Example 1. This is the later photo. '' is replaced by ``Figure 7 is a photograph showing the shape of the fibers after defibration obtained in Example 1, Figure 8 is a photograph showing the shape of the fibers after defibration obtained in Example 2, Figure 9 is a photograph of the shape of the fiber after defibration obtained in Comparative Example 1.''

Claims (2)

[Claims] (1) A screw extruder is used to melt and knead the thermoplastic resin, water, and an auxiliary agent that helps the water to disperse into the thermoplastic resin. By passing the fibrous material through at least one throttling orifice provided between the screw outlet and the die,
A method for producing an ultrafine fiber bundle, which comprises extruding a fiber bundle in which a large number of ultrafine fibers having a diameter of 200 μm or less are bundled in a substantially parallel state through a die at the tip of an extruder. (2) The method for producing an ultrafine fiber bundle according to claim 1, wherein gas is blown toward the ultrafine fiber bundle from at least one direction of a die to defibrate the ultrafine fiber bundle.