JP2005154976A - Fibrous structural material used as industrial material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fibrous material having an excellent durability and biodegradability as an industrial material which can not be achieved by conventional technology, i.e. consisting of a polylactic acid fiber having biodegradability and a high strength, excellent in mechanical characteristics such as abrasion resistance, etc. <P>SOLUTION: This fibrous material used as the industrial material consists of the polylactic acid fiber having 30-5,000 dtex fineness, 4.5-7.0 cN/dtex strength and 15-40 % elongation, and contains 0.1-5 wt. % fatty acid bisamide and/or an alkyl-substituted type fatty acid monoamide. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a fiber structure for industrial materials using polylactic acid fibers. More specifically, a new fiber structure for industrial materials having excellent durability and biodegradability, using polylactic acid fibers that have biodegradability, high strength, and excellent mechanical properties such as wear resistance. About the body.

  Since polylactic acid fibers are fibers that are biodegradable and obtained from non-petroleum-based raw materials, they have attracted attention in recent years as fibers having a small environmental load even when discarded, and their application development has been promoted. For example, drained garbage bags, seedling mats, herbicidal sheets for vegetation, tea bags, towels, gloves, napkins, etc. are applications that make use of the characteristics of polylactic acid fibers that are mainly biodegradable and made of non-petroleum materials. In addition, polylactic acid fiber has a unique luster, good color development when dyed, and has a smooth touch and texture, making use of its fashionability, blouse, shirt, scarf, handkerchief, lining Development is progressing for use. Furthermore, it is being put to practical use in interior applications such as car option mats, household roll carpets and rugs.

  On the other hand, for industrial materials, after using polylactic acid fiber as a product, many uses have been proposed by taking advantage of the biodegradable feature that the load at the time of disposal is low. The successes are still limited. Industrial materials applications such as building construction nets, civil engineering sheets, land nets, sandbags, tents, tarpaulins, etc. are particularly required to have high strength, high toughness, wear resistance, etc., and are used as products. Therefore, the conventional polylactic acid fiber is too risky to assure safety and has been praised.

  In order to be able to be applied to industrial materials with peace of mind, it has the mechanical properties and durability of the polyester fiber level with a proven track record, and the properties are maintained for a certain period of time, after which the properties are no longer necessary. From the point of view, fibers that are biodegradable are ideal. Conventional polylactic acid fibers have a problem that the mechanical properties such as strength and wear resistance are slightly inferior to the required properties, and the durability is insufficient.

  Conventionally, fiber structures for industrial materials have been used by weaving polyethylene terephthalate, polyethylene or polypropylene fibers. However, since the fiber structure for industrial materials composed of these non-biodegradable fibers is not particularly recoverable, it has a problem that it is abandoned in the natural environment even after its use and accumulates without being decomposed. Was. However, polylactic acid fibers developed in recent years are made of non-petroleum raw material biodegradable polymers, and improved mechanical properties and polymer cost reduction are progressing. Yes. For example, Patent Literature 1 and Patent Literature 2 are disclosed for techniques used as a fiber structure for industrial materials. Further, Patent Document 3 and Patent Document 4 are disclosed regarding polylactic acid to which a fatty acid amide is added.

  Patent document 1 has as its subject “Providing a material fabric that eliminates the essential drawbacks of polyester fiber and polyamide fiber, has a thin, light, strong texture, and is biodegradable”. "At least one of the warp or weft of the woven fabric is composed of polylactic acid fibers, the sum of the density of the constituent yarns of the woven fabric is 180 yarns / 吋 or more, the fabric weight is 40 to 200 g / square meter, and dry heat This is solved by a woven fabric made of polylactic acid fiber, which is heat-treated at a temperature of 150 to 180 ° C. ”.

  However, in the prior art, the improvement of the abrasion resistance of the polylactic acid fiber, which is important as the industrial material fabric of the present invention, and the polylactic acid fiber containing the fatty acid amide compound for achieving the improvement are completely described. There is no.

  Further, Patent Document 2 has the subject “Provision of civil engineering sheet excellent in weather resistance and impact resistance”, and the subject is “a civil engineering sheet using a woven fabric at least partially, A civil engineering sheet characterized in that the warp and / or weft of the fabric is an aliphatic polylactic acid fiber having a melting point of 130 ° C. or higher. ”

  However, there is no description in the prior art about the improvement of the abrasion resistance of the polylactic acid fiber and the polylactic acid fiber containing a fatty acid amide compound for achieving the improvement.

  Patent Document 3 has an object of “providing a novel polymer composition having lactic acid as a main component and having suppressed degradability.” The subject is “a polylactic acid polymer having lactic acid as a main component”. (1) paraffin having a molecular weight of 150 or more, (2) polyethylene having a molecular weight of 50,000 or less, (3) modified polyethylene having a molecular weight of 50,000 or less, and (4) the number of carbon atoms in one molecule (hereinafter referred to as carbon number). An abbreviation) having 10 or more aliphatic alcohols, (5) aliphatic carboxylic acids having 10 or more carbon atoms and their metal salts, (6) amides of aliphatic carboxylic acids having 10 or more carbon atoms, (7) having 10 or more carbon atoms A polylactic acid composition obtained by mixing 0.1 to 4% by weight of at least one compound selected from the group consisting of esters of aliphatic carboxylic acids of (8) and esters of aliphatic alcohols having 10 or more carbon atoms. It is said that it will be solved. The prior art relates to a polylactic acid fiber containing a fatty acid amide, and is intended to control the rate of biodegradation according to the application and the environment in which it is used. It is said that this can be achieved by forming a composition obtained by mixing seeds with polylactic acid and a molded product thereof. One type ((6)) describes “aliphatic carboxylic acid amides having 10 or more carbon atoms”. However, the fatty acid amide in Patent Document 4 is substantially a fatty acid monoamide, and when a fatty acid monoamide is used, the monoamide is highly reactive, so that it reacts with polylactic acid at the time of melting and remains a monoamide compound. The ratio remaining in the fiber is reduced, and the fiber structure for industrial material is not high strength and improved in mechanical properties such as wear resistance and durability. In addition, the reaction may reduce the molecular weight of polylactic acid, resulting in a decrease in fiber properties, particularly strength. In addition, fatty acid monoamides have high sublimation properties, so that when they are spun, they adhere to the equipment wall as a sublimate and deteriorate workability, and aggregated sublimates adhere to the fibers and cause thread breakage and dirt. May occur.

Patent Document 4 has the subject “To make an aliphatic polyester molded article exhibit transparency and crystallinity at the same time.” The subject is “aliphatic polyester and aliphatic carboxylic acid amide, aliphatic carboxylate, Forming an aliphatic polyester composition containing at least one transparent nucleating agent selected from a group of compounds having a melting point of 40 to 300 ° C. comprising an aliphatic alcohol and an aliphatic carboxylic acid ester, and crystallizing at the time of molding or after molding It is said that it can be solved by “A method for producing an aliphatic polyester molded article having both transparency and crystallinity”. The prior art is a technique in which polylactic acid contains an aliphatic carboxylic acid amide as a crystallization nucleating agent in order to simultaneously exhibit transparency and crystallinity of an aliphatic polyester molded article. This technique is used as a compound that serves as a crystallization agent that simultaneously satisfies the transparency and crystallinity of an aliphatic polyester molded product such as polylactic acid, as an aliphatic carboxylic acid amide, an aliphatic carboxylate, an aliphatic alcohol, and an aliphatic carboxyl. It is said that it is effective to contain at least one compound group consisting of acid esters having a melting point of 40 to 300 ° C.
JP 2002-339190 A JP 2000-220054 JP-A-8-183898 JP-A-9-278991

  An object of the present invention is to overcome the above-described problems and provide a fiber structure for industrial materials made of a novel polylactic acid fiber that could not be achieved by the prior art. That is, a novel fiber structure for industrial materials having excellent durability and biodegradability, which is made of polylactic acid fibers having biodegradability, high strength and excellent mechanical properties such as wear resistance. It is to provide.

The object of the present invention can be achieved by the following means.
1. A fiber structure for industrial materials using at least a part of a woven fabric, wherein the warp and / or weft of the woven fabric contains a fatty acid bisamide and / or an alkyl-substituted fatty acid monoamide in an amount of 0.1 to A fiber structure for industrial materials, comprising a polylactic acid fiber containing 5% by weight.
2. 2. The fiber structure for industrial materials according to 1, wherein the polylactic acid fiber has a fineness of 30 to 5000 dtex, a strength of 4.5 to 7.0 cN / dtex, and an elongation of 15 to 40%.
3. 3. The fiber structure for industrial materials according to item 1 or 2, wherein the polylactic acid fiber is an original yarn.
4). The fiber structure for industrial materials according to any one of items 1 to 3, wherein the cover factor is 500 to 5000 and the basis weight is 40 to 2000 g / m ² .
5). 5. The textile structure for industrial materials according to any one of 1 to 4, which is a base fabric for use in bags, tents, tarpaulins, canvases or civil engineering sheets.

  Provided is a new fiber structure for industrial materials having excellent durability and biodegradability, using polylactic acid fibers having biodegradability, high strength and excellent mechanical properties such as wear resistance. be able to.

  Hereinafter, the present invention will be described in detail.

  The fiber structure for industrial materials of the present invention has excellent durability and biodegradability using a polylactic acid fiber having biodegradability, high strength and excellent mechanical properties such as wear resistance. It is a new fiber structure for industrial materials.

  The polylactic acid polymer used as the raw material of the polylactic acid fiber used in the fiber structure for industrial materials of the present invention is a polymer of lactic acid oligomers such as lactic acid and lactide, and the optical form of L-form or D-form of lactic acid in the polymer. A purity of 90% or higher is preferable because of a high melting point. The optical purity of the L-form or D-form is more preferably 97% or more. A blend of polylactic acid having an optical purity of 90% or higher in the L form and polylactic acid having an optical purity of 90% or higher in the D form at a ratio of 70/30 to 30/70 is preferable because the melting point is further improved. When the molecular weight of the polylactic acid polymer is 50,000 to 500,000 in terms of weight average molecular weight, it is preferable that the balance between mechanical properties and moldability is good. In addition, components other than lactic acid may be copolymerized as long as the properties of polylactic acid are not impaired. Polymers and particles other than polylactic acid, matting agents, plasticizers, flame retardants, antistatic agents, Additives such as odorants, antibacterial agents, antioxidants, heat resistance agents, light resistance agents, ultraviolet absorbers, and coloring pigments may be included as necessary. As a polymer other than polylactic acid, for example, an aliphatic polyester polymer such as polycaprolactone, polybutylene succinate, and polyethylene succinate can be used as a plasticizer. However, the polylactic acid fiber in the present invention is a biodegradable and non-petroleum-based raw material, and is used as a product with a small environmental impact even when discarded. Therefore, a blend of petroleum-based polymers, copolymerization of the components, etc. It is more preferable to avoid as much as possible, and it is preferable not to use various additives, not to mention heavy metal compounds and environmental hormone substances, as well as all compounds that are currently expected to be concerned.

  The polylactic acid fiber in the present invention has a higher strength than conventional ones, and is particularly characterized in that the wear resistance is remarkably improved. This excellent property is achieved by incorporating at least one of fatty acid bisamide and alkyl-substituted fatty acid monoamide in the polylactic acid fiber of the present invention.

  The fatty acid bisamide in the present invention refers to a compound having two amide bonds in one molecule such as saturated fatty acid bisamide, unsaturated fatty acid bisamide, aromatic bisamide, etc., for example, methylene biscaprylic acid amide, methylene biscapric acid amide. , Methylene bis lauric acid amide, methylene bis myristic acid amide, methylene bis palmitic acid amide, methylene bis stearic acid amide, methylene bis isostearic acid amide, methylene bis behenic acid amide, methylene bis oleic acid amide, methylene bis erucic acid amide , Ethylene biscaprylic amide, ethylene biscapric amide, ethylene bislauric acid amide, ethylene bismyristic acid amide, ethylene bispalmitic acid amide, ethylene bisstearic acid amide, ethylene bis Sostearic acid amide, ethylene bis behenic acid amide, ethylene bis oleic acid amide, ethylene bis erucic acid amide, butylene bis stearic acid amide, butylene bis behenic acid amide, butylene bis oleic acid amide, butylene bis erucic acid amide , Hexamethylene bis stearic acid amide, hexamethylene bis behenic acid amide, hexamethylene bis oleic acid amide, hexamethylene bis erucic acid amide, m-xylylene bis stearic acid amide, m-xylylene bis-12-hydroxy stearic acid amide P-xylylene bis-stearic acid amide, p-phenylene bis-stearic acid amide, p-phenylene bis-stearic acid amide, N, N′-distearyl adipic acid amide, N, N′-distearyl sebacic acid amide, N N'-dioleyl adipic acid amide, N, N'-dioleyl sebacic acid amide, N, N'-distearyl isophthalic acid amide, N, N'-distearyl terephthalic acid amide, methylenebishydroxystearic acid amide, ethylene Examples thereof include bishydroxystearic acid amide, butylene bishydroxystearic acid amide, and hexamethylene bishydroxystearic acid amide.

  The alkyl-substituted fatty acid monoamide referred to in the present invention refers to a compound having a structure in which an amide hydrogen such as a saturated fatty acid monoamide or an unsaturated fatty acid monoamide is replaced with an alkyl group, such as N-lauryl lauric acid amide, N- Palmityl palmitic acid amide, N-stearyl stearic acid amide, N-behenyl behenic acid amide, N-oleyl oleic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl erucic acid amide, N-oleyl And palmitic acid amide. The alkyl group may have a substituent such as a hydroxyl group introduced into its structure. For example, methylol stearamide, methylol behenic acid amide, N-stearyl-12-hydroxystearic acid amide, N- Oleyl-12-hydroxystearic acid amide and the like are also included in the alkyl-substituted fatty acid monoamide of the present invention.

  In the present invention, fatty acid bisamides and alkyl-substituted fatty acid monoamides are used, but these compounds have lower amide reactivity than ordinary fatty acid monoamides, and are less likely to react with polylactic acid during melt molding. In addition, since many of them have a high molecular weight, they generally have good heat resistance and are difficult to sublimate. In particular, fatty acid bisamides can be more preferably used because they are less reactive with polylactic acid due to the lower reactivity of amides, and are high in heat resistance and difficult to sublime due to their high molecular weight.

  It is important that the polylactic acid fiber in the present invention contains 0.1 to 5% by weight of fatty acid bisamide and / or alkyl-substituted fatty acid monoamide. Preferably it is 0.5 to 3 weight%. If the amount is less than 0.1% by weight, the effect of the present invention cannot be sufficiently obtained. On the other hand, if it exceeds 5% by weight, the strength of the polylactic acid fiber is lowered and the production yield is lowered. By setting the content of fatty acid bisamide and / or alkyl-substituted fatty acid monoamide in the above range, the surface friction coefficient of the fiber is reduced, and the strength and wear resistance required as a fiber structure for industrial materials and repeated use can be reduced. The durability can be imparted. The fatty acid bisamide and the alkyl-substituted fatty acid monoamide may be added singly or a plurality of components may be mixed and used. Even when mixed and used, the entire mixture may be contained in an amount of 0.1 to 5% by weight.

  Further, the polylactic acid fiber in the present invention is preferably provided with an oil containing a smoothing agent as a main component and containing a surfactant, an antistatic agent, an extreme pressure agent component, and the like. A preferred oil agent composition is, for example, a non-aqueous oil agent obtained by diluting an alkyl ether ester as a smoothing agent, an alkylene oxide adduct of a higher alcohol as a surfactant, and an organic phosphate salt as an extreme pressure agent with mineral oil. By applying the oil agent, the surface friction coefficient of the polylactic acid fiber is reduced, and it is possible to further improve the wear resistance in the fiber structure for industrial materials.

  The polylactic acid fiber used in the fiber structure for industrial materials of the present invention preferably has a fineness of 30 to 5000 dtex, a strength of 4.5 to 7.0 cN / dtex, and an elongation of 15 to 40%. Even if the fineness is less than 30 dtex and exceeds 5000 dtex, the basic performance of the fiber structure for industrial materials of the present invention is maintained. However, in order to increase production efficiency and supply at a low cost, a fineness of less than 30 dtex is disadvantageous. On the other hand, fibers exceeding 5000 dtex are difficult to handle and the fineness range is preferred. If the strength is less than 4.5 cN / dtex, the strength as a fiber structure for industrial materials is slightly lowered, and polylactic acid fibers exceeding 7.0 cN / dtex are difficult to industrially produce with the current technology. The elongation is an elongation that is manifested when the strength in the present invention is achieved. For example, if it is less than 15%, excellent wear resistance cannot be obtained, and if the elongation exceeds 40%, a high strength is obtained. It becomes impossible.

  The polylactic acid fiber in the present invention is preferably an original yarn. This is because the polylactic acid fiber used in the fiber structure for industrial materials of the present invention is required to have high strength, so that a decrease in strength in the dyeing process is avoided. The colorant added to the polylactic acid original yarn in the present invention is a specific inorganic, organic pigment and dye suitable for polylactic acid fibers. Specifically, oxide-based inorganic pigments excluding lead, chromium and cadmium, ferrocyanide inorganic pigments, silicate inorganic pigments, carbonate inorganic pigments, phosphate inorganic pigments, carbon black, aluminum powder, bronze powder and titanium powder Selected from inorganic pigments such as coated mica, organic pigments such as phthalocyanine organic pigments, perylene organic pigments, isointoserinone organic pigments, and heterocyclic dyes, helinone dyes, perylene dyes and thioindio dyes Or a combination of two or more. For example, inorganic pigments include oxides such as titanium oxide, zinc white, titanium yellow, zinc-iron-based brown, titanium-cobalt green, cobalt green, cobalt blue, copper-iron black, and ferrocyans such as bitumen. , Silicates such as county blue, carbonates such as calcium carbonate, phosphates such as manganese violet, carbon black, aluminum powder and bronze powder, and titanium powder-coated mica are used, lead, chromium and cadmium Inorganic pigments containing heavy metals such as are not used. As the organic pigment, phthalocyanine series such as copper phthalocyanine blue, copper phthalocyanine green and brominated copper phthalocyanine green, perylene series such as perylene scarlet, perylene la, perylene maroon, isoindolinone, etc. are used. Examples of the dye include anthraquinone series such as Solvent R.50, Solvent R.111, Solvent B.94, Solvent V.50, Solvent G.3, and heterocyclic systems such as Solvent Y.33 and Solvent Y. .111, Solvent Y.54, Helinone series such as Solvent O.60, Solvent R.135, Solvent R.179, perylene series such as Solvent G.5, thioindio series such as Vat R.1 are used.

  The colorant used for the polylactic acid original yarn in the present invention is used in combination of one or more selected from the above inorganic pigments, organic pigments and dyes. Preferably, the colorant is adjusted by using two or more kinds. By using a combination of two or more colorants, it is possible to produce a subtle color tone that can be compared to conventional dyed polylactic acid fibers.

  The addition concentration of the colorant varies depending on the kind of the dye, but is 100 to 30,000 ppm, preferably 500 to 10,000 ppm as the total amount of the colorant per polymer weight. The colorant can also be used in combination with a commonly used dispersant.

  The fiber structure for industrial materials of the present invention is characterized in that a woven fabric is used for at least a part thereof. The form of the woven fabric is not particularly limited, and a plain weave, a twill weave, a satin weave, an entangled weave, or the like can be applied depending on the application, but usually a plain weave or an entangled weave is adopted.

Also, when constituting the fiber structure for industrial materials only woven, woven fabric, it is preferable cover factor is 500 to 5000, and basis weight is 40~2000g / m ^2. If it is in this range, the properties such as waterproofness, windproof property, lightness and elasticity that are required for bags, tents, tarpaulins, canvases, civil engineering sheets, etc. will be good. When the cover factor is less than 500, misalignment is likely to occur, and since the fiber density is low, the cover factor cannot be used for applications such as tents, canvases, and civil engineering sheets that require water resistance and wind resistance. On the other hand, when the cover factor exceeds 5000, the fiber density is too high, and the process passability in the weaving process and the handleability as various textile products become poor. Further, if the basis weight is less than 40 g / m ² , the fabric is too thin to obtain sufficient elasticity, and if it exceeds 2000 g / m ² , the fabric is too thick and weight reduction cannot be obtained, which is not preferable. The cover factor in the present invention is a value obtained by the following formula (I).

Cover factor K = D1 ^{/ 2} * N + E1 ^{/ 2} * M (I)
(However, D: warp fineness (dtex), N: warp density (main / inch), E: weft fineness (dtex), M: weft density (main / inch))
Moreover, the fiber structure for industrial materials of the present invention does not need to be composed only of woven fabric. For example, in the case of imparting waterproofness and windproof property, vinyl chloride, ethylene vinyl alcohol (EVA), polyurethane, etc. Coating, laminating, and dipping can be performed with this resin. In addition, for a fully biodegradable fiber structure for industrial materials, coating, laminating, and dipping are performed using biodegradable resins such as polylactic acid, polycaprolactone, polybutylene succinate, and polyethylene succinate. It is also suitable. Or the form etc. which bonded the woven fabric and the nonwoven fabric may be sufficient, and a structure can be designed in the range which does not inhibit workability.

  The fiber structure for industrial materials in the present invention uses polylactic acid fibers having excellent wear resistance, so that not only the fibers rub against each other, but also rubs and heavy machinery such as earth and sand, stones, rocks and concrete. It is not easily damaged by trampling, etc., and has extremely excellent durability. On the other hand, after a certain period of use, it is buried in the soil or is biodegraded if recovered and composted, and eventually decomposes almost completely, so there is little environmental impact. It is useful as a fiber structure for industrial materials.

As described above, the fiber structure for industrial material of the present invention is a novel fiber structure for industrial material having excellent durability and biodegradability, and industries such as bags, tents, tarpaulins, canvases, civil engineering sheets, etc. It can be suitably used for material use. The bag in the present invention means a bag-like fiber structure in general, and examples thereof include sandbag bags, flexible container bags (flexible bag), compost bags, shopping bags, and the like. In addition, the canvas in the present invention means all thick fabrics having a basis weight of 227 g / m ² or more, such as sails of sailing ships, balloons, paragliders, hang glider materials, building materials, furniture materials, saddles, aprons, etc. Is mentioned. Further, the civil engineering sheet in the present invention means all sheet-like fiber structures used in various civil engineering works, for example, coating materials, filter materials, water permeable materials, protective materials, basic materials, retaining wall materials, Examples include ground improvement materials.

  A preferable example is shown below as a manufacturing method of the polylactic acid fiber used for the fiber structure for industrial materials of this invention.

  The polylactic acid in the present invention can be synthesized using a known method, but it is preferable that the polylactic acid itself has a good color tone and that residual oligomers and monomers such as lactide are reduced. As a specific method, for example, as described in JP-A-7-504939, it is preferable to use a metal deactivator, an antioxidant, or the like, to lower the polymerization temperature, and to suppress the catalyst addition rate. Moreover, the amount of residual oligomers and monomers can be greatly reduced by subjecting the polymer to reduced pressure treatment or extraction with chloroform or the like.

  The polylactic acid used for producing the polylactic acid fiber in the present invention uses a high viscosity polymer having a relative viscosity of 2.5 to 5. Preferably, it is the range of 3.5-4.5. When a polymer having a relative viscosity of less than 2.5 is used, it may not be possible to stably obtain a polylactic acid fiber having high strength and excellent wear resistance according to the present invention. On the other hand, when a high-viscosity polymer having a relative viscosity exceeding 5 is used, it is difficult to produce a stable yarn, and polylactic acid fibers having excellent uniformity may not be obtained.

  The method for incorporating the fatty acid bisamide and / or the alkyl-substituted fatty acid monoamide into the polylactic acid fiber in the present invention is not particularly limited, and examples thereof include the following methods. First, as a kneading step, polylactic acid and fatty acid bisamide and / or alkyl-substituted fatty acid monoamide are dried and then supplied to a nitrogen-sealed kneading extruder to produce a kneading chip. Next, melt spinning is performed by subjecting the kneading tip to an extruder. In the kneading step, a kneaded chip containing a high ratio of fatty acid bisamide and / or alkyl-substituted fatty acid monoamide is prepared (made as a master chip), and the fatty acid bisamide and / or alkyl-substituted fatty acid is used in the spinning machine. A normal polylactic acid chip can be blended and diluted so that the monoamide has a desired content. In the melt spinning process, it is possible to knead the polylactic acid and the fatty acid amide more finely by installing a static kneader between the extruder and the pack or in the pack. Aggregation of fatty acid amides and bleed-out to the fiber surface may cause deterioration of operability due to soiling of guides and rollers, and may cause uneven physical properties and dyeing spots of fiber products. Is preferably finely dispersed in polylactic acid.

  Further, kneading and melt spinning may be performed in the same process, and for example, the following method can be used. In the first method, polylactic acid and fatty acid bisamide and / or alkyl-substituted fatty acid monoamide are dried and then supplied to an extruder sealed with nitrogen, and the polylactic acid and fatty acid bisamide and / or alkyl-substituted kneaded by the extruder This is a method in which a kneaded polymer melt of a fatty acid monoamide is further finely kneaded by a static kneader, discharged from a discharge hole, and melt-spun. The second method is a method in which polylactic acid and fatty acid bisamide and / or alkyl-substituted fatty acid monoamide are separately melted, the melt is finely kneaded by a static kneader, discharged from a discharge hole, and melt-spun. is there.

  The fatty acid bisamide and / or the alkyl-substituted fatty acid monoamide may be contained in an amount of 0.1 to 5% by weight based on the total amount of the blend polymer. By setting the content of the fatty acid amide to 0.1% by weight or more, the surface friction coefficient of the fiber can be reduced, and the process passability in the weaving process can be improved. Further, by setting the content of the fatty acid amide to 5% by weight or less, an excess of the fatty acid amide bleeds out from the molten polymer during kneading or spinning, and this causes sublimation or decomposition to cause smoke generation. It is possible to prevent deterioration of operability such as deterioration or contamination of the extrusion kneader or melt spinning machine due to excessive sublimates or decomposition products of fatty acid amides. Further, if the content of the fatty acid amide is 5% by weight or less, in the spinning process, bleeding out of the molten polymer of the fatty acid amide is suppressed, so that the discharge of the polymer from the discharge hole is stable and uniform. It is preferable because fibers having physical properties can be obtained. The content of the fatty acid amide is preferably 0.5 to 3% by weight. In the present invention, fatty acid bisamides and / or alkyl-substituted fatty acid monoamides are used. However, these are preferable lubricants because they are less likely to sublimate and have better heat resistance than prior art fatty acid monoamides. In particular, fatty acid bisamides can be preferably used because they are less reactive with polylactic acid because of the lower reactivity of amides, and are high in heat resistance and difficult to sublimate because of their high molecular weight.

  When the polylactic acid fiber in the present invention is produced by the melt spinning method, the spinning temperature is 190 to 250 ° C, preferably 200 to 240 ° C. Immediately below the spinneret, the upper end is 0 to 15 cm from the base, and the range from 5 to 100 cm from the upper end is surrounded by a heating tube and / or a heat insulating tube, and the spun yarn passes through a high temperature atmosphere of 200 to 280 ° C. It is preferable to make it. The spinning filament is not cooled immediately, but is gradually cooled through a high-temperature atmosphere surrounded by the heating tube and / or the heat insulating tube, thereby relaxing the orientation of the spun filament and uniformity among the filaments. And a high-strength polylactic acid fiber can be obtained.

  The unstretched filament that has passed through the high-temperature atmosphere is then cooled and solidified by blowing air at 10 to 50 ° C., preferably 15 to 30 ° C. The air cooling device may be a horizontal blowing type or an annular blowing type.

  The unstretched filament that has been cooled and solidified is then applied with an oil agent. The oil agent contains a smoothing agent as a main component and includes a surfactant, an antistatic agent, an extreme pressure agent component, and the like, but it is necessary to have an oil agent composition excluding components active on polylactic acid fibers. A preferred oil agent composition is, for example, a non-aqueous oil agent obtained by diluting an alkyl ether ester as a smoothing agent, an alkylene oxide adduct of a higher alcohol as a surfactant, and an organic phosphate salt as an extreme pressure agent with mineral oil.

  The unstretched filament yarn provided with the oil is wound around a take-up roll (1FR) and taken up. The speed of the take-up roll, that is, the spinning speed is 300 to 3000 m / min. Although the physical properties of the polylactic acid fiber of the present invention can be obtained even at a spinning speed of less than 300 m / min, it is difficult to employ industrially because the production efficiency is low. On the other hand, when the spinning speed exceeds 3000 m / min, the high-strength polylactic acid fiber in the present invention cannot be stably obtained.

  The undrawn yarn taken up at the spinning speed is drawn continuously without being wound once. As with the take-up roll (1FR), a Nelson roll having two rolls as one unit is a yarn feeding roll (2FR), a first draw roll (1DR), a second draw roll (2DR), and a third draw roll. (3DR) and the relaxation roll (RR) are arranged side by side, and the yarn is sequentially wound to perform a drawing heat treatment. Usually, between 1FR and 2FR, a stretch of 0.5 to 10%, preferably about 1 to 5% is performed to converge the yarn. 1FR is heated to 50 to 80 ° C., preferably 55 to 70 ° C., and the take-up yarn is preheated and sent to the next drawing step. The first stage of stretching is performed between 1DR and 2DR. At this time, the draw point, that is, the necking point, is positioned on the 1DR roll so that it is stably located within a few centimeters immediately before leaving the roll. And the draw ratio of the 1st step is set. However, these conditions need to be changed in consideration of the degree of orientation of the undrawn yarn. Usually, the temperature of 2FR is 80 to 120 ° C., preferably 90 to 110 ° C., the temperature of 1DR is 90 to 130 ° C., preferably 100 to 120 ° C., and the first stage draw ratio is 10 of the total draw ratio. It is set to ˜70%, preferably 20 to 50%. Within the range of the above conditions, the draw point is set so as to be positioned in the vicinity of the 2FR roll upper exit. Furthermore, in order to set the draw point so as to be positioned at the upper outlet of the 2FR roll, the roll is preferably a satin roll with low friction.

  The second stage stretching is performed between 1DR and 2DR, and 2DR is 110 to 150 ° C, preferably 115 to 145 ° C. In the case of two-stage stretching, the remaining stretching of the first-stage stretching ratio is performed between the total stretching ratios. In the case of three-stage stretching, the remaining stretching ratio is divided into two stages. The temperature of 3DR when performing three-stage stretching is 120 to 150 ° C, preferably 125 to 145 ° C. The yarn that has finished the two-stage drawing or the three-stage drawing is subjected to a relaxation treatment of 0.5 to 10%, preferably 1 to 7% with the RR, not only to remove the distortion caused by the hot drawing, but also to the drawing. It is possible to fix the highly oriented structure achieved by the above, or to relax the orientation of the amorphous region and lower the thermal shrinkage rate. RR uses an unheated roll or a roll heated to 150 ° C. or lower. Usually, RR becomes a temperature of 90 to 150 ° C. regardless of the presence or absence of heating due to the heat brought in by the yarn heated at the time of hot drawing.

  Moreover, in the manufacturing method of the polylactic acid fiber of this invention, it is preferable to set it as multistage extending | stretching of 2 to 5 steps, preferably 3 to 5 steps. When the number of drawing stages is one, high-strength fibers are difficult to obtain because it cannot be drawn at a high magnification. Further, when the number of stretching stages is 5 or more, it is not preferable because the equipment is enlarged and the manufacturing process becomes complicated.

  Thus, a polylactic acid fiber suitable for the fiber structure for industrial materials of the present invention having the above physical properties can be obtained.

  Next, manufacture of the fiber structure for industrial materials of this invention is demonstrated.

First, a woven fabric is produced by a conventionally known method using the polylactic acid fiber. Although it does not specifically limit as a form of a woven fabric, Conventionally well-known forms, such as a plain weave, a twill weave, a satin weave, and a tangle weave, can be employ | adopted suitably. At this time, although it depends on the use, the weave density may be set so that the cover factor of the woven fabric is 500 to 5000 and the basis weight is 40 to 2000 g / m ² . Thereafter, the obtained woven fabric is subjected to processing such as pasting with a non-woven fabric, coating, laminating, dipping or the like as necessary. As the nonwoven fabric to be bonded, those having an average fineness of 1 to 20 dtex and a basis weight of 40 to 500 g / m ² are suitable. This nonwoven fabric is laminated on one side or both sides of the woven fabric by a known method such as needle punching. For processing such as coating, laminating, and dipping, a conventionally known method can be employed, and a resin to be used can be appropriately employed depending on the application and required characteristics. For example, vinyl chloride, ethylene vinyl alcohol (EVA), and polyurethane are used as waterproof sheets, and polylactic acid, polycaprolactone, polybutylene succinate, and polyethylene succinate are used as fully biodegradable sheets. A degradable resin can be suitably used.

  Hereinafter, the present invention will be described in detail with reference to examples. The characteristic definitions and measurement methods described in the text and examples are as follows.

A. 25 mL of chloroform was added to a sample having a relative viscosity of 0.5 g, and the mixture was stirred for 5 hours to dissolve the polymer. Then, chloroform was added to dilute to 50 mL. The diluted solution was measured using a Schott AVS500 auto viscometer at a test temperature of 30 ° C., and the relative viscosity ηr was determined based on the following formula. The measurement was performed 3 times, and the average value was taken.

ηr = t / t ₀
t: number of seconds during which the solution flows
t ₀ : Flowing down seconds of solvent (chloroform only) Fineness Measured according to JIS L1090.

C. Strength and elongation Measured according to JIS L1013. The strength was measured using a Tensilon tensile tester manufactured by Orientec Corp. under the conditions of a test length of 250 mm and a tensile speed of 300 mm / min. The strength is a value obtained by dividing the strength by the total fineness of the sample.

D. Dry heat shrinkage rate Measured at 120 ° C. according to JIS L1013. Three samples were collected from the same sample and measured, and the average value was obtained.

E. Abrasion Resistance of Woven Fabric A test piece having a diameter of 120 mm was cut out from the woven fabric, and attached to a Taber abrasion tester specified in ASTM D1175, and subjected to 1000 rotational wear using a wear wheel CS # 10 and a load of 500 g. Then, the surface abrasion state of this test piece was observed, and the wear resistance was evaluated by the following index.

A: Almost not worn ○: A little worn Δ: Worn considerably, but not torn ×: Worn significantly and torn is conspicuous Durability of fabric (strong retention)
A durability model test was conducted by the following method and evaluated by the strength retention of the woven fabric.

First, after laying a 2m square woven fabric on the concrete alley, from the height of 2m above the alley, weigh a total of 200kg boulders with a diameter of 5-10cm (50cm square) Was dropped. After repeating this operation 20 times, the cobblestone was removed, and a strip-shaped test piece having a length of 25 cm and a width of 7.5 cm was cut out from the center of the woven fabric. Next, the strength S ₁ of this test piece was measured, and the strength retention rate was determined by the following formula using this S 1 and the strength S ₀ before the test. The strength was determined by the same method as in C above, and the average value of n number 20 was obtained.

Strength retention (%) = (S ₁ / S ₀ ) × 100
H. Biodegradability of woven fabric The woven fabric was put into compost maintained at a temperature of 58 ° C. and a moisture content of 65% by weight, taken out after one month, and observed.

    (Double-circle): Decomposition | disassembly has progressed considerably and there exist many locations with a large hole.

    ○: Decomposition is in progress and there are some holes.

    Δ: There are no holes, but the texture has begun to thin partially.

    X: Almost the same as before landfill.

[Production Example 1] (Production of polylactic acid)
Polymerization of lactide prepared from L-lactic acid with an optical purity of 99.5% in the presence of bis (2-ethylhexanoate) tin catalyst (lactide to catalyst molar ratio = 10000: 1) at 180 ° C. for 200 minutes in a nitrogen atmosphere. Polylactic acid P1 was obtained. The relative viscosity of the obtained polylactic acid was 4.0.

[Production Example 2] (Production of polylactic acid containing 4% by weight of EBA)
After drying P1 and ethylene bis-stearic acid amide (EBA) [“Alfro H-50S” manufactured by NOF Corporation], EBA was continuously metered so that P1: EBA = 96: 4 (weight ratio). Polylactic acid P2 containing 4% by weight of EBA was obtained by using a biaxial kneading extruder with a cylinder temperature of 220 ° C. while adding to P1.

[Production Example 3] (Production of polylactic acid containing 4% by weight of SS)
Polylactic acid P3 containing 4% by weight of SS was prepared in the same manner as in Production Example 2 except that EBA was changed to N-stearyl stearamide (SS) [Nika Amide S] manufactured by Nippon Kasei Co., Ltd., an alkyl-substituted monoamide. Obtained.

[Production Example 4] (Production of polylactic acid containing 4% by weight of SA)
Polylactic acid P4 containing 4% by weight of SA was obtained in the same manner as in Production Example 2, except that EBA was changed to monoamide stearamide (SA) [“Alfro S-10” manufactured by NOF Corporation].

[Production Example 5] (Production of polylactic acid containing 15% by weight of colorant)
P1: Coloring agent (carbon black) = 85: 15 (weight ratio) In the same manner as in Production Example 2, polylactic acid P5 containing 15% by weight of coloring agent was obtained.

Example 1
Chip blend (EBA 1% by weight) so that the weight ratio is P1: P2 = 3: 1, charged into a hopper, melted at 220 ° C. with an extruder, and then placed on a spin block heated to 220 ° C. The molten polymer was introduced into the spinning pack and spun from a 192-hole die having a hole diameter of 0.6 mm.

  A heating cylinder of 30 cm was attached just below the base and heated so that the temperature in the cylinder was 250 ° C. Here, the in-cylinder atmosphere temperature is an air layer temperature in a central portion of the heating cylinder length and a portion 1 cm away from the inner wall.

  An annular blow-off chimney was attached immediately below the heating cylinder, and cold oil at 30 ° C. was blown onto the yarn at a rate of 30 m / min to cool and solidify, and then an oil was applied. Oils include iso-C24 alcohol / thiodipropionic acid ester (40% by weight), C11-15 alcohol AOA / thiodipropionic acid ester (30% by weight), trimethylolpropane AOA distearate (10% by weight), C8 alcohol AOA ( 10% by weight), hydrogenated castor oil (7% by weight), and stearylamine EO15 (3% by weight) diluted with mineral oil to 20% by weight were used as a non-aqueous oil agent.

  The unstretched yarn provided with the oil agent was wound around a take-up roll (1FR) rotating at a speed of 500 m / min. Next, the take-up yarn was continuously stretched by 1.5% between the take-up roll and the yarn feeding roll (2FR) without being wound once, and subsequently subjected to three-stage hot drawing. Thereafter, the film was wound after giving 3.0% relaxation (FIG. 1). 1FR is 60 ° C, 2FR is 100 ° C, the first stretching roll (1DR) is 115 ° C, the second stretching roll (2DR) is 140 ° C, the third stretching roll (3DR) is 140 ° C, and the relaxation roll (RR) Was not heated.

  In addition, the entanglement nozzle was attached between the relaxation roll and the winder, and the entanglement was imparted to the fiber by injecting 0.2 MPa of compressed air. The first stage draw ratio was set to 34% of the total draw ratio, and the second stage and third stage draw ratios were both set to 33%. Thus, 1100 dtex-192 fil polylactic acid fiber was obtained. The obtained fiber exhibited good yarn properties such as a strength of 5.4 cN / dtex, an elongation of 32.3%, and a dry heat shrinkage of 2.3%.

Four of these fibers were combined to obtain 4400 dtex-768 fil, and a plain woven fabric having a warp / weft of 9 / inch, a basis weight of 320 g / m ² and a cover factor of 1194 was produced. The obtained woven fabric was excellent in wear resistance and durability, and had moderate biodegradability in soil.

Example 2
A polylactic acid fiber and a woven fabric comprising the same were obtained in the same manner as in Example 1 except that only P2 (EBA was 4% by weight) was used as the raw material polymer. The obtained woven fabric was extremely excellent in wear resistance and durability, and had moderate biodegradability in soil.

Example 3
A polylactic acid fiber and a woven fabric comprising the same were obtained in the same manner as in Example 1 except that the charging ratio of P1 and P2 was 12.3: 1 by weight (EBA was 0.3% by weight). The obtained woven fabric was excellent in wear resistance and durability, and had moderate biodegradability in soil.

Example 4
A polylactic acid fiber and a woven fabric comprising the same were obtained in the same manner as in Example 1 except that P3 was used instead of P2. The obtained woven fabric was excellent in wear resistance and durability, and had moderate biodegradability in soil.

Example 5
The woven fabric obtained in Example 1 was dyed under the following conditions. When the fiber was unwound from a part of the woven fabric after the dyeing process and the strength was measured, 4.0 cN / dtex was found to be lower in strength than before the dyeing process (5.4 cN / dtex). The resulting woven fabric was slightly inferior in wear resistance and durability compared to the woven fabric before dyeing (Example 1), but exhibited moderate characteristics and moderate biodegradability in the soil. I had it.

<Dyeing conditions>
-Dye: Dianix Navy Blue ERFS 200 (2% owf)
-Auxiliary agent: pH adjuster (0.2 g / l)
-Temperature x time: 110 ° C x 40 minutes Example 6
Polylactic acid fiber in the same manner as in Example 1 except that the chip blend (EBA 1 wt%, colorant 0.3 wt%) was made so that the weight ratio was P1: P2: P5 = 3: 1: 0.08. And a woven fabric comprising the same. The obtained woven fabric was excellent in wear resistance and durability, and had moderate biodegradability in soil.

Example 7
A nonwoven fabric having a basis weight of 200 g / m ² and a thickness of 2 mm made of a polylactic acid nonwoven fabric of 5 dtex using the same raw material as in Example 1 (1% by weight of EBA) is overlapped on both sides of the woven fabric obtained in Example 1. Then, a civil engineering sheet was produced by performing needle punching (needle density 30 / cm ² , needle depth 13 mm). The obtained civil engineering sheet was extremely excellent in wear resistance and durability, and had moderate biodegradability in soil.

Example 8
Four fibers obtained in Example 1 are combined to make 4400 dtex-768 fil, and a plain fabric with a warp of 3 / inch, a weft of 4 / inch, a basis weight of 120 g / m ² , and a cover factor of 464 is produced. did. The obtained woven fabric was slightly inferior to the woven fabric of Example 1, but had wear resistance and durability, and moderately biodegradable in the soil.

Comparative Example 1
A polylactic acid fiber and a woven fabric comprising the same were obtained in the same manner as in Example 1 except that only P1 was used as the raw material polymer. The obtained woven fabric had good biodegradability, but was inferior in wear resistance and durability, and did not sufficiently satisfy the properties as a fiber structure for industrial materials.

Comparative Example 2
A polylactic acid fiber and a woven fabric comprising the same were obtained in the same manner as in Example 1 except that P4 was used instead of P2. The obtained fiber has low strength, and the obtained woven fabric has good biodegradability, but is inferior in wear resistance and durability, and required characteristics as a fiber structure for industrial materials. Was not enough. It is suggested that these poor characteristics are caused by a decrease in the molecular weight of polylactic acid caused by stearamide, which is a fatty acid monoamide.

Comparative Example 3
A nonwoven fabric having a basis weight of 200 g / m ² and a thickness of 2 mm made of a polylactic acid nonwoven fabric of 5 dtex using the same raw material as that of Comparative Example 1 is overlapped on both the front and back surfaces of the woven fabric obtained in Comparative Example 1. Civil engineering sheet was prepared by applying a book / cm ² and a needle depth of 13 mm. The obtained civil engineering sheet had good biodegradability, but was inferior in wear resistance and durability, and did not sufficiently satisfy the characteristics as a civil engineering sheet.

It is a figure which shows a direct spinning drawing apparatus.

Explanation of symbols

1: Hopper 2: Extrusion kneader (Extruder)
3: Spin block 4: Spin pack 5: Base 6: Heating cylinder 7: Chimney 8: Oiling device (oiling roller)
9: Take-up roll (1FR)
10: Yarn supply roll (2FR)
11: First stretching roll (1DR)
12: Second stretching roll (2DR)
13: Third stretching roll (3DR)
14: Relaxing roll (RR)
15: Entangling nozzle 16: Winder

Claims (5)

A fiber structure for industrial materials using at least a part of a woven fabric, wherein the warp and / or weft of the woven fabric contains a fatty acid bisamide and / or an alkyl-substituted fatty acid monoamide in an amount of 0.1 to A fiber structure for industrial materials, comprising a polylactic acid fiber containing 5% by weight. The fiber structure for industrial materials according to claim 1, wherein the polylactic acid fiber has a fineness of 30 to 5000 dtex, a strength of 4.5 to 7.0 cN / dtex, and an elongation of 15 to 40%. The fiber structure for industrial materials according to claim 1 or 2, wherein the polylactic acid fiber is an original yarn. Cover factor 500 to 5000, and mass per unit area industrial materials for fibrous structure described in any one of claims 1 to 3, characterized in that a 40~2000g / m ^2. The fiber structure for industrial materials according to any one of claims 1 to 4, which is a base fabric for bags, tents, tarpaulins, canvases or civil engineering sheets.

Images