JPH04136251A - Nonwoven fabric having excellent water absorption performance - Google Patents

Abstract

PURPOSE:To obtain the title nonwoven fabric composed of a conjugate fiber consisting of a specific copolymer polyester and non-compatible thermoplastic polymer of a thermoplastic polyamide, and having an ultrafine fiber-forming component in one kind of the polymer and useful as a padding cloth, medical clothing, etc. CONSTITUTION:The objective nonwoven fabric consisting essentially of a conjugate fiber consisting of a incompatible thermoplastic polymer obtained by blending (A) polyester copolymer composed of a dicarboxylic unit, a diol unit and an unit expressed by formula I [(x) and (y) are 0 or 1; Z is formula II (R1 is 3-18C hydrocarbon; R2 is alkylene; n is 5-29); and HLB value of the compds. in formula III shows >=0.5 monovalent radical, being 1-50wt.% in the content of unit expressed by formula I and having 0.5-1.5dl/g intrinsic viscosity with (B) a thermoplastic polyamide at a weight ratio of the component A/the component B of 85/15 to 15/85, and being ultrafine fiber-forming component in one or more kinds of the polymers and constructing at least one side with fibers formed by cleaving the above-mentioned component or a fibrous layer obtained by interlacing the cloven fibers with the uncloven fibers.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention: A fiber absorbent material suitable for use in medical applications such as phenol material, wiping cloth, interlining, clothing, and disposable surgical gowns. This is related to fiber-entangled nonwoven fabrics with high performance.

(Prior art) Conventionally, the surface layer consists of a layer of densely intertwined F-2 microfibers,
At the bottom of the layer is an entangled layer of ultrafine fiber bundle fibers. Immediately after spinning, the ultrafine fibers are gathered together and partially adhered to form a single fiber; one component of the fibers is interposed radially between other components. W&A fibers with a chrysanthemum-shaped cross section, multilayer bimetal fibers, sea-island fibers consisting of two or more components, multiple arrays of microfibers continuous in the fiber axis direction, combined with other components, and/or one fiber. The fibers are bonded together to form a single fiber, which is then made into a fiber web using so-called ultrafine fiber-forming fibers such as two-polymer interlayer fibers, which are needle punched and then brought into contact with a high-speed fluid stream to form fibrils. It is manufactured by a method of forming a nonwoven fabric structure by finely entangling it from the side door, and this product is used, for example, as a leather-like sort in which the N part of the densely entangled nonwoven fabric is a grain layer.

In recent years, polyester fibers represented by polyethylene terephthalate have played an important role in the textile field, especially in the non-woven fabric field, especially in baby diapers and diaper liners.
The field of sanitary materials such as sanitary products, the field of non-hygienic materials such as counter cloths for the restaurant industry, drainage bags for sinks for kitchen utensils, and the medical field such as base fabrics and fixing sheets for Notsu medicines, surgical gowns for hospitals, and masks. However, nonwoven fabrics made of polyester fibers have been widely used. Among these many nonwoven fabric products, especially those such as baby diapers and sanitary products are required to have water absorption performance that is more durable than conventional products.

(Problem to be Solved by the Invention) A fiber web made of conventional ultrafine fiber-forming fibers (dividable fibers) is brought into contact with a high-speed fluid stream to simultaneously branch the splittable fibers into ultrafine fibers or bundles of ultrafine fibers. Non-woven fabric structures that are finely entangled or non-woven/fabric structures that have such a surface layer have a tendency to become fluffy and cling to hands and skin when the non-woven fabric is used alone. It has the disadvantage that it is too soft and stiff and cannot hold its shape. In addition, because the ultrafine fiber morphology is relatively homogeneous, the strength of the nonwoven fabric is obtained even though the entanglement strength is not sufficient, which is not necessarily preferable depending on the application. In addition, with regard to water absorption performance, most of the products to date have been processed after surface treatment with oil, etc., and although this has good initial performance, after a certain amount of use, the surface oil falls off and the performance deteriorates. There were many things that were extremely low.

Among these, wet-type nonwoven fabrics for diaper surface materials and sanitary bat surface materials always go through the papermaking process in water during the manufacturing process, so the method of coating the fiber surface with a hydrophilic agent is The curing agent falls off, and the final product is only one that does not maintain sufficient performance.

An object of the present invention is to provide a fiber-entangled nonwoven fabric in which the fibers are densely entangled on at least one side, which is bulky and stiff, and furthermore has high nonwoven fabric strength, durability, and excellent water absorption performance. It is.

(Means for Solving the Problems) That is, the present invention mainly provides dicarboxylic acid units, diol units, and general formula 1, in which X and y each represent 0 and f2 represent 1, and Z
is the formula % formula % (wherein, R1 represents a hydrocarbon group having 3 to 18 carbon atoms, and R
t represents an alkylene group, and n represents the average degree of polymerization 15~
29) and is represented by the general formula % formula % (represents a monovalent group whose H, L, and B values determined by the Davis method in the compound shown are 50 or more) The content of the structural unit represented by the general formula (1) is 1 to 50% by weight, and the temperature is 30°C in an isobaric Ti mixture of phenol and tetrachloroethane.
Two types of incompatible thermoplastic polymers, a copolymerized polyester (A) and a thermoplastic polyamide (B), each having an intrinsic viscosity of 0.5 to 1.5 dg/g, are used. , (to 1)/(B) or 85/15 to 15/85 in weight ratio
A non-woven fabric composed of Temero composite fibers as main fibers, wherein at least one type of polymer of the composite fibers is a fine fiber-forming component, and at least a portion of each fine fiber-forming component is are non-woven fabrics having different cross-sectional shapes, and at least one side of the non-woven fabric has a fiber layer in which at least a portion of the fibers are split and formed and intertwined with r-fine fibers or unsplit fibers. be.

One component constituting the fiber used in the present invention is the specific copolyester mentioned above, and the dicarboxylic acid unit, which is one of the essential structural units of this copolyester, is composed of two dicarboxylic acid units. 2 in carfoquinol group
It is an r-dimorphic structural unit excluding hydroxyl groups, and is represented by the general formula (wherein R1 is a divalent organic group and L represents a single bond). The divalent organic group represented by R3 includes, for example, a divalent aromatic hydrocarbon group such as p-phenylene group, m-phenylene group, naphthalenediyl group, (biphenyl)diyl group, octamethylene group, hydrogen chloride group, etc. Examples include divalent hydrocarbon groups such as groups. In the present invention, the copolymerized polyester may contain only one type of dicarboxylic acid unit or may contain two or more types of dicarboxylic acid units, but the copolymerized polyester has excellent mechanical performance required for fiber applications. From the viewpoint of obtaining a polyester, it is desirable that 70 mol% or more of the dicarboxylic acid units be terephthaloyl groups.

The diol unit, which is one of the essential structural units of the copolymerized polyester constituting the fiber used in the present invention, is a structural unit obtained by removing two hydrogen atoms from two hydroxyl groups from a diol, and is generally It is represented by the formula % formula % (in the formula, R4 represents a divalent organic group). Examples of the divalent organic group represented by R4 include ethylene group, trimethylene group, tetramethylene group,
Divalent aliphatic hydrocarbon groups such as pentamethylene group, hexamethylene group, 2.2-methyltrimethylene group, 3-methylpentamethylene group, nonamethylene group, 2-methyloctamethylene group: dimethylnoclohexane-α ,α°
-Divalent ring hydrocarbon groups such as diyl group; divalent aromatic groups such as 2,2-nophenylpropane-4°,4''-diyl group, diphenylsulfone-4,4-noyl group, etc. The copolymerized polyester of the present invention may contain only one type of diol unit, or may contain two or more types of diol units. From the viewpoint of obtaining a polymerized polyester, 70 mol% or more of the diol units are carbon atoms such as ethylenedioxy, trimethylenedioxy, tetramethylenedioquine, pentamethylenedioquine, and hexamethylenedioxy groups. Preferably, it is a divalent structural unit obtained by removing two hydrogen atoms in two hydroxyl groups from a linear alkylene glycol having 2 to 6 numbers.

The structural unit represented by general formula (1), which is an essential structural unit of the copolymerized polyester of the present invention, has the general formula 0-Cl1
- CI+, -0- CH, -Z (1-1) (wherein Z is as defined above) a structural unit represented by
Including structural units represented by the general formula % formula % (wherein Z is as defined above), structural units represented by the general formula % formula % (wherein Z is as defined above), etc. do. The structural units represented by the general formula ([) usually have an ester bond (-C-0-) between them or with the dicarboxylic acid unit or diol unit.
Alternatively, it is incorporated into the main chain of the copolyester by forming an ether bond (-0-). R1 in formula (■)
As the hydrocarbon group having 3 to 18 carbon atoms represented by, for example, n
-brovyl, isopropyl, n-butyl, isobutyl,
5ec-butyl, Lert-butyl, n-pentyl, n
-octyl, 2-ethylhexyl, n-dobnol, n-
Preferred are alkyl groups having 3 to 18 carbon atoms such as stearyl, cycloalkyl groups having 3 to 18 carbon atoms such as cyclohexynyl, and aryl groups having 6 to 18 carbon atoms such as phenyl and nonylphenyl. When the number of carbon atoms in the hydrocarbon group R1 is 2 or less or 19 or more, it has excellent surface leakage,
A copolyester that provides a fiber aggregate with excellent water absorption and water retention cannot be obtained. In addition, the alkylene group represented by R in formula (n) may be an ethylene group, a propylene group or An alkylene group having 2 to 4 carbon atoms such as a group is preferable, and an ethylene group is more preferable. Two or more alkylene groups may coexist in the same group Z as R2. Formula (n
n in ) is a number representing the average degree of polymerization of the polyokine alkylene moiety, and is a number within the range of 15 to 29. n is 15
If the number is less than 1, it will not be possible to provide a copolymerized polyester with excellent surface leakage and excellent water absorption and water retention properties. If n is a number greater than 29, no effect greater than that achieved if n is in the range of 15 to 29 will no longer be achieved. The value of n is 20 to 20, since the copolyester that provides a fiber aggregate with particularly excellent surface leakage properties and particularly excellent water absorption and water retention properties is obtained with as little inconvenience as possible, such as coloring.
Preferably, the number is within the range of 25. General formula (1)
The monovalent group Z in the formula (II) not only has a structure represented by formula (II), but also has a H, LJ, and valency determined by the Davis method in a compound represented by the general formula (I[[) of 50 or more. It is essential to satisfy the structural conditions for the number. According to the Davies method in the present invention [
1. L, B, and valence are, for example, G.T.
J, T. Davies), E.K.Rezoal (
E., K., Rideal) co-authored “Interfacial Phenomena”.
ena) 2nd edition J (1983, published by Academic Press (USA), pages 372-374, co-edited by Nishi, Imai, and Kasai, "Surfactant Handbook" (July 5, 1960, Sangyo Tosho Co., Ltd.) (Published by the company), page 313 (2) Edited by the Japan Oil Chemists' Association, "Oil and Fat Chemistry Handbook Revised 2nd Edition" (November 30, 1971, published by the Maruzenji Company), No. 7
As described on page 10, etc., it is derived according to the formula (H, L, B values) = 7 + (total number of hydrophilic groups) ÷ (total number of lipophilic groups). Here, the numbers of groups in typical examples of hydrophilic groups and lipophilic groups are as follows.

Parent group Number of lipophilic groups Number of groups -01J -Cut 0.475CFI,
--0,475 =CH -C--0,475 Z in general formula (I) is H, L, B, GB determined by Davis method in the compound represented by general formula (1)
When i is a number less than 50, the surface leakage of the obtained copolyester is not high, and the fiber aggregate obtained using it cannot exhibit sufficient water absorption and water retention. . The Davis method for a compound in which Z is represented by the general formula (III) has the advantage that the ease of surface leakage in the resulting copolymerized polyester and the water absorption and water retention properties of the fiber aggregate obtained using the same are particularly enhanced. The obtained H, L, and B values are 7.0 to 15.
It is desirable to set the number within the range of 0, 8.0 to 13
, 5 is more preferable.

The copolymerized polyester of the present invention may contain only one type of structural unit represented by general formula (I), or may contain two or more types of structural units, but the content of the structural unit may be determined in the copolymerized polyester. It is within the range of 1 to 50% by weight, and 2 to 4% by weight.
It is preferably within the range of 0% by weight, especially 3 to 30% by weight.
Particularly preferred is within the range. If the content is less than 1% by weight, the resulting copolyester will have insufficient surface leakage, and if it exceeds 50% by weight, the resulting copolyester will have poor performance such as strength. may decrease.

The copolymerized polyester constituting the fiber used in the present invention may mainly consist of dicarboxylic acid units, diol units, and f-filament structural units represented by the general formula (1), or may contain other structural units. It may be present in a small amount such that the action and effect are not lost. Such optional structural units include a p-oxybenzoic acid unit represented by the formula, a p-(β-oxinethoquino)amic acid unit represented by the formula υ, a fragrant acid unit, etc. Hydroquinocarboxylic acid unit which is a divalent structural unit excluding the hydrogen atom in the hydroxyl group and phenolic or alcoholic hydroxyl group in the group; glycerin unit represented by the formula 0, formula %, formula C) I, -0- CILCII, -C-CH, -0 CI (, -0 is a trivalent structural unit obtained by removing three hydrogen atoms in the hydroxyl group of 3[1) from a triol, such as a trimethylolpropane unit represented by A tetraol unit, which is a tetravalent structural unit obtained by removing four hydrogen atoms among the four hydroxyl groups from a tetraol, such as a pentaerythritol unit represented by the formula %, is represented by the formula 1. Tricarboxylic acid unit, which is a trivalent structural unit obtained by removing three hydroxyl groups among the three carboxyl groups from tricarboxylic acid, such as trimellitic acid unit, trimesic acid unit shown by the formula Examples include a tetracarboxylic acid unit, such as a mellitic acid unit, which is a tetravalent structural unit obtained by removing four hydroxyl groups among four carboxyl groups from a tetracarboxylic acid.

The copolymerized polyester constituting the fiber used in the present invention has an intrinsic viscosity of 0.5 to 1.0% when measured at 30'C in a mixed solvent of equal weights of phenol and tetrachloroethane.
It is within the range of 5d12/g. Intrinsic viscosity is 0.5dC/
If the copolyester has a weight of less than 10 g, the strength and other IN properties will be insufficient, and yarn breakage will be significant when subjected to melt spinning. On the other hand, the intrinsic viscosity is 1.5 dll/g
If the copolymerized polyester exceeds 100%, the melt viscosity may become too high and the spinnability may be poor. The intrinsic viscosity of the copolyester is set to 0.0, because mechanical performance is particularly good and troubles during the fiberization process can be reduced.
It is preferably within the range of 6 to 1, odc/g.

The copolyester constituting the fiber used in the present invention is disclosed in, for example, Japanese Patent Publication No. 43-19037,
It is manufactured according to the known method described in JP-A No. 1234420, JP-A-1-236236, and the like.

For example, a dicarboxylic acid corresponding to a desired dicarboxylic acid unit such as terephthalic acid is directly esterified with a diol corresponding to a desired diol unit such as ethylene glycol, or a lower alkyl ester of terephthalic acid such as dimethyl terephthalate is used. Either an ester-forming derivative of a dicarboxylic acid corresponding to a desired dicarboxylic acid unit such as a dicarboxylic acid unit is transesterified with a diol corresponding to a desired diol, or a dicarboxylic acid corresponding to a desired nocarboxylic acid unit is reacted with an alkylene such as ethylene oxide. The esters of dicarboxylic acids and diols consist of reacting the oxides to form their oligomers. In the second stage reaction consisting of polycondensation up to , Z is as defined above) to the reaction system. Ester forming agent represented by A in general formula (IV) #
Preferred examples of organic groups having an I group include organic groups having the following structure.

-C[l, -CHCH.

\. / (ka') ,,)b @ )CHt
CHOH CIl, OH (2,3-nohythokoquinopropyl group) Comonomers represented by the general formula ([V) include, for example, polyoquinoethylene glycol-6-propyl-glycidyl ether, polyoquinoethylene glycol-n
-propyl-2,3-dihydroquine propyl ether,
Polyoquinoethylene glycol-t-butyl-gurindyl ether, polyoquinoethylene glycol-t-butyl-2,3-dihydroxypropyl ether, polyoquinoethylene glycol-n-octyl-glinonol ether, polyoquinoethylene glycol-n-octyl-
2,3-dihydroquinopropyl ether, polyoxyethylene glycol-2-ethylhexyl-quinol-2,3-dihydroxypropyl ether, polyoxyethylene glycol-2-ethylhexyl-quinol-2,3-dihydroxypropyl ether, polyoxyethylene glycol-n-dotecyl Grindyl ether, polyoxine ethylene glycol-n-dodecyl-2,3-dihydroquinopropyl ether, polyquinoethylene glycol-〇-stearyl-grindyl ether, polyoxine ethylene glycol-n-stearyl-23-dihydroquipropyl ether , polyquine ethylene glycol-phenyl-glycidyl ether,
Polyoxyethylene glycol phenyl-2,3-dihydroxypropyl ether, polyoxyethylene glycol-nonylphenyl-glycidyl ether, polyoxyethylene glycol-nonylphenyl-2,3-dihydroquine propyl ether, polyoxyethylene glycol-chlorohexyl ether Glycidyl ether, polyoxyethylene glycol-cyclohexyl-2,3-dihydroxypropyl ether, octyl-glycanol ether of polyoxyethylene glycol/polyoxypropylene glycol copolymer, polyoxyethylene glycol/polyoxypropylene glycol copolymer Octyl-2,3-dihydroxypropyl ether of the combination, dodecyl glycidyl ether of the polyoxy/ethylene glycol/polyoxypropylene glycol copolymer, n-togenol of the polyoxy 7-functional ethylene glycol/polyoquinopropylene glycol copolymer -2,3 dihydroquine propyl ether and the like can be selected from 11 or 2 or more.

In addition, at any stage of the above series of manufacturing steps, dihydroquine carboxylic acid or its ester-forming derivative, triol, tetraol, tricarboxylic acid or its ester-forming derivative, tetracarboxylic acid or its ester-forming derivative, etc. A small amount of a comonomer that provides a structural unit that the copolymerized polyester of the present invention may optionally have may be added to the reaction system.

The copolymerized polyester constituting the present invention may contain optional additives, such as catalysts, anti-coloring agents, heat resistant agents, fluorescent bleaches, retardant agents, antioxidants, matting agents, colorants, Inorganic fine particles may also be included. In particular, there is a risk that the polyoquine alkylene chain portion may be oxidized under high temperature conditions such as melt spinning conditions, resulting in a decrease in the degree of polymerization, coloring, and other inconveniences. Addition of fluorescent bleach may give preferable results.

At present, it is not possible to clearly explain why the composite fiber containing the copolymerized polyester as one component of the present invention exhibits excellent water absorbency, but as mentioned above (IV
) When copolymerizing monomers of formula ), this is probably because the polyoxine alkylene chains hanging as side chain groups are effective. By setting an appropriate HLB value and length (n = 15 to 29) of the side chain portion in the process considered in the present invention, a more effective water absorption effect and good fiberization processability can be maintained. This is the first time that polymerized polyester has been discovered.

In addition, when copolymerizing components such as linear polyalkylene glycol, the amount of copolymerization must be considerably increased in order to obtain the desired water absorption performance level.
The physical properties of the polymer or crystallinity are markedly reduced, as well as the heat resistance. On the other hand, when a side chain type polyalkylenoglycol is copolymerized, as in formula (IV), the amount of copolymerization is smaller, and the fiber-forming process properties are better and the fiber properties are better. It was discovered that the following can be obtained. Moreover, as shown in equation (n), n=15
~29, HLB 5 or higher tenacity (I found it to be even better overall.

When n in formula (II) increases, heat resistance during spinning becomes poor and spinnability decreases, and copolymerizability when copolymerizing monomers of formula ([V)] becomes insufficient. Therefore, we have come to the conclusion that it is best to set n to 29 or less.

Another important requirement of the present invention is that the fibers constituting the nonwoven fabric of the present invention are fibers that can split at least a portion of the A polymer component or the B polymer component to form fine fibers with irregular shapes. Yes, such fibers are produced by selecting two incompatible thermoplastic polymers (A) and (B), melting them in different melting systems, and subjecting the melts to joining and splitting at least twice at the spinning head. It is obtained by dividing each molten polymer stream into fine fiber-forming components in a repeating mixing system and discharging them from a spinneret, followed by stretching, crimping, heat setting, etc., and the fineness is, for example, l-12. It should be about 1 denier. In the cross section of the resulting fiber, each fine fiber-forming component is mutually dispersed or arranged, or in a mixed state of dispersion and arrangement, and at least a part of each fine fiber-forming component is dispersed with a different cross-sectional shape. It is what forms the form.

The boronamide of polymer B, which is the other polymer used, includes nylon-6, nylon-610
, nylon-66, metakylene diamine nylon, nylon 12, etc. as main components, and may also be a polyamide containing a small amount of a third component. Additionally, these may contain small amounts of additives, optical brighteners, stabilizers, and the like.

The composite ratio of polymer A and polymer B should be in the range of 15:85 to 85:15 in terms of weight ratio. If the content of either component is less than 15% by weight, spinnability will be poor, which is preferable.

Next, in the present invention, the fibers thus obtained are cut into table fibers having a cut length of, for example, 30 to 130 mm, and passed through a cart or a random univer to form a random web, parallel web, or cross-wrap web. and other fiber webs. It is preferable that the fibrous web is sufficiently entangled with fibers by a needle punching method so that it will not be transferred to the next processing step or deformed during post-processing. The punch density of needle punch varies depending on the thickness of the fiber web, but is generally 10 to 100 punches/cLl! Punch densities in the range of . Further, in some cases, it is not necessary to perform needle punching on a thin fibrous web. The thus obtained fiber sheet is irradiated with at least one side of a high-pressure jet fluid flow to form fine fibers by interlocking and splitting the fibers, as well as to form whisker-like fine fibers, and to entangle them. Water is preferred as the high-pressure jet fluid stream, but water at room temperature, water heated to about 35 to 80°C, or water added with a treatment agent to promote splitting and splitting of fibers can be used. . MaL
1.Is water pressure determined by the ease with which fibers split and split?
Usually, it is set in the range of 10 to 200 kg/am.

The fiber entanglement treatment using a high-pressure jetted fluid stream is performed so that the surface fiber layer of the nonwoven fabric on both sides that is in contact with the fluid stream has a density that is at least 0.03 g / c■3 It is preferable to carry out the process until a high density is achieved in order to improve the smoothness of the surface of the non-woven fabric and give the non-woven fabric a stiff texture. However, nonwoven fabrics with a small basis weight, for example, about 100g/1m! If the basis weight is below, it is difficult to obtain a sufficient density gradient or the density of the fiber layer is difficult to measure, in which case the apparent density of the nonwoven fabric should be set to O.13g.
/ca'' or more, preferably O, 15g/am' or more.

Regarding the method of measuring the apparent density of the surface fiber layer and intermediate layer in the present invention, first, when a nonwoven fabric is obtained by contacting a fluid flow only from one side: Slice the nonwoven fabric into two equal parts, measure the thickness of the sliced nonwoven fabric under a load of 20g/am, and calculate the apparent density along with the basis weight data.Also, by contacting both sides of the sheet with a fluid stream. When obtaining a nonwoven fabric, the nonwoven fabric can be divided into three equal parts in the thickness direction and the apparent density of each slice can be measured in the same manner as above.In the present invention, the intermediate layer (i) is the middle layer of the sliced material. This is the second one that shows that.

Regarding the apparent density of the nonwoven fabric of the present invention measured in this way, in the case of a nonwoven fabric in contact with a fluid flow on only one side, the apparent density of the fibrous layer on both sides that was in contact with the fluid flow or the fibrous layer on the other side. It is preferable to have an apparent density that is 003 g/cm or more higher than that of the intermediate layer, and in a nonwoven fabric that has been subjected to fluid flow treatment from both sides, both the fiber layers on both sides should have an apparent density that is 003 g/cm or more higher than the intermediate layer. Or preferable.

The basis weight of the nonwoven fabric of the present invention varies depending on the use, for example,
For sanitary facing materials, 15 to 40 g/ff11,
30 to 200 g/ffl' for wiping fiber sheets, wiping cloths, interlining clothing, clothing, tablecloths, medical gowns, synthetic leather base fabrics, etc., and 50 to 2000 g/m' for civil engineering and industrial materials, etc. be.

In the production of the nonwoven fabric of the present invention, thermal binder fibers containing a polymer having a relatively low softening temperature as a sheath component are used.
It is also preferable to mix the fibers in a range of 40% by weight to fix the fibers #1 in applications where morphological stability of the nonwoven fabric is particularly required.

The entangled nonwoven fabric of the present invention can be smoothed by contacting the surface where the fibers are tightly intertwined with a heated calender surface, heated embossing treatment, or colored by dyeing, printing, etc. It can be made into a non-woven fabric product.

Next, the present invention will be explained with reference to the drawings. FIG. 1 is a schematic diagram of the cross-sectional structure of the nonwoven fabric of the present invention, where (A) is a nonwoven fabric with two sides densely intertwined, Ca> is a nonwoven fabric with both sides densely entangled, l is a nonwoven fabric, and 2 is a densely entangled nonwoven fabric. The intertwined fiber layer, 3, is a coarsely intertwined fiber layer. Figures 2 (a) to (c) are examples of schematic diagrams of the cross-sectional structure of fibers constituting the nonwoven fabric of the present invention, and 4.4" is a component of fine fibers. It is a schematic diagram illustrating the state of split and split fibers, where 5 is an unsplit fiber portion, and 6 and 7 are split and split fine fibers.

The nonwoven fabric of the present invention can be used for sanitary napkins, diapers, facing materials for sanitary products such as breast-feeding bats, wiping fiber sheets, wiping cloths, interlining, padded cotton, clothing, medical supplies such as disposable surgical gowns, sheets, etc. Useful for tablecloths, covers, bags, civil engineering and industrial materials, etc.

In the present invention, the excellent water absorbency was evaluated by measuring the water absorption length using the Pyrex method.

To explain more specifically, a single raw cotton sample to be measured with a single yarn denier of 2 dr and a cut length of 51 mm is placed on a card and random univer to obtain an average basis weight of 60 g/Il! After laminating two fiber webs and needle punching with a #40 needle at 70 punches/cI11'', the hole diameter was 0.
Water pressure gradually increases from 30kg/am' to 150kg/a from a high-pressure water jet nozzle with 25II 1m nozzles arranged in a row.
After spraying a water stream up to m' and performing a three-stage treatment on the nonwoven fabric on a moving wire mesh support from one side, it was air-dried.
Further, it was heat-treated at 150° C. for 1 minute in an auto dryer to obtain a nonwoven fabric for water absorption measurement. The nonwoven fabric for measurement was partially immersed in water colored with red ink and hung in a diagonal manner, and the wicking length was measured after 10 minutes. The wicking length was measured with n=10 in each of the vertical and horizontal directions of the nonwoven fabric,
The sum of the vertical and horizontal average values was defined as the wicking length.

A major feature of the nonwoven fabric of the present invention is that it has excellent water absorption performance and excellent durability with almost no decline even after washing. By coating the surface of ordinary polyester fibers with various processing agents, treatment agents, finishing agents, etc., it is possible to impart some initial water absorption. For example, polyvinyl alcohol-based processing agents, polyester ether-based processing agents (for example, Takamatsu Yushi Co., Ltd. S R-10)
Examples include hydrophilic antifouling agents such as 00), various nonionic, anionic, and cationic hydrophilic oil agents, and combination agents thereof. All of the nonwoven fabrics whose surface is not coated with these processing agents have some initial performance, but when washed, the performance drops dramatically, whereas the fibers of the present invention have a drastic drop in performance. Confirm that it does not, 3
It was. Regarding washing durability, the measurement sample was
Washing was repeated 10 times according to the LO217-103 method, the wicking length after 10 times was measured, and the water absorption performance was evaluated.

The reason why the nonwoven fabric of the present invention exhibits excellent water absorption performance cannot be clearly stated, but it is due to the partially split fibrillated structure of the nonwoven fabric of the present invention that has a fine capillary effect and the copolymerized polyester component that has excellent hydrophilicity. This seems to be due to a synergistic effect.

Next, the present invention will be explained according to examples. The washing process in the examples was carried out according to JIS L-0217-103 method. Add and dissolve 2 g of synthetic detergent for clothing into water IQ at a liquid temperature of 40°C to prepare a washing liquid. Add the sample and, if necessary, the load fabric to this washing solution at a bath ratio of 1:30 and start operation. After processing for 5 minutes, stop the operation and dehydrate the sample and load fabric in a dehydrator. Next, replace the washing liquid with fresh water at room temperature, rinse for 2 minutes with the same bath ratio, dehydrate, rinse again for 2 minutes, and air dry. Repeat the above operation 10 times and close the measurement sample f2 after 10 times.

[Examples 1 to 31 Predetermined amounts of terephthalic acid and ethylene glycol were charged into an esterification reactor, and the esterification reaction was carried out at 230°C under a pressure of 2.5 kg/am' for 3 hours. Next, this reaction product was heated to 230°C and transferred to a polycondensation tank, and a compound represented by the following formula (II) was added to this system as shown in Table 1, L! f moss was added, and predetermined amounts of a hindered phenol antioxidant, antimony dioxide, phosphorous acid, and an antifoaming agent were added to prepare a polycondensation reaction system. The temperature of the polycondensation reaction system was raised from 230°C to 280°C,
Gradually reduce the O and lmmHg, and then perform the polycondensation reaction at 280°C until the melt viscosity of the system reaches a predetermined value, n0C, tH! 50(CH2CH20),,CH,C
lICH2O (■) 1 (LB value = 10.7 The obtained cut polymer was crystallized at 190°C under vacuum, and supplied as an A polymer component to a spinning head kept at 290°C, and -10,000 B polymer component m at 30℃
-Using nylon-6 with a hardness of 2η: 116 in cresol, melt and extrude it separately from polymer A and supply it to the spinning head.
A/B-7/3 were combined using a static mixer and the process of joining and dividing was repeated 5 times at a spinning temperature of 290°C.
A fiber having a cross-sectional shape similar to that shown in FIG. 2 (c) was obtained. This fiber was drawn, crimped, and heat-set to obtain a fiber with a fineness of 2 denier. This fiber was cut into a fiber length of 51a+n, passed through carding and random univer, and turned into a wk web with an average basis weight of 60 g/m'. Two sheets were laminated and needle punched with a needle size of #40 to 70 bunches/cI11". After that, nozzles with a hole diameter of 0.25n+m were arranged in a row, and a water jet with a water pressure of 30 kg/cm' gradually increased to 150 kg/cIn+ was jetted from the high-pressure water jet nozzle to the nonwoven fabric on the moving wire mesh support. Perform 3 stages of processing from one side f2.

The obtained nonwoven fabric is subjected to water treatment, and a large number of whisker-like fine fibers are generated on the two sides, and the undivided fibers and fine fibers are densely intertwined to form a two-dimensional structure, and most of the lower part is This non-woven fabric, which mainly consists of vertically oriented fibers and is bientangled, is sliced into two parts with a bandmann knife at the middle of the thickness, and the apparent density of each part is determined. This f is 0.27g/cm' on the second side and 0 on the back side.
．． It was 21g/cm'. The dense surface of this nonwoven fabric was heated to 130° C. and pressed against the bicalender surface to perform a smoothing treatment. This non-woven fabric is flexible and drapes well.
It had a high cutting strength of 0.47 kg/■1 and was suitable for applications such as clothing and tablecloths.

Measurement of wicking length of non-woven fabric under standard conditions (20°C, 165%R)
1 (). The results are shown in Table 1. From Table 1, it can be seen that L nonwoven fabrics with good water absorbency and durability were obtained.

Comparative Example 121 In Comparative Example 1, a nonwoven fabric made of polyethylene terephthalate single fiber with a single yarn denier of 2 d and a cut length of 57 mm was produced in the same manner as in Example 1, and its water absorption performance was measured, and one of the fabrics had no performance at all.

Comparative Example 2 uses polyethylene terephthalate as the A polymer (1. In the same manner as in Example 1, a nonwoven fabric is prepared without fiberization, and its water absorption performance is measured.
child.

Example 4.5: In Example 1, instead of the compound represented by the formula ([[), the compound represented by the formula (III) shown in Table 1 was added in two amounts. A copolymer was similarly obtained for the two outer sides of F, and this was used as polymer A to obtain a nonwoven fabric in the same manner as in Example 1. The measurement results of the wicking length of the nonwoven fabric are shown in Table 1. A durable non-woven fabric having good water absorbency was obtained.

) ILB value = 87 [Examples 6 to 9] Example 6 uses a compound represented by formula (IV) in place of the compound represented by formula (IT) in Example 1, and Example 7 uses formula (XV) Example 8 is a compound represented by the formula (V[
), and in Example 9, a copolymer was obtained in the same manner except that the compound represented by the formula (■) was added in the amount of f2 shown in Table 1. Fiberization was performed in the same manner as in 1 to obtain a nonwoven fabric. Table 1 shows the measurement results of the wicking length of the nonwoven fabric. A woven fabric with durability and good water absorbency *Lt:';F was obtained.

) ILB value -96, however, the above C, L7 groups are n C4
H-.CHCHy group.

e C,H,0(CI(tcl(to)!@C1(tc[(
CI(! (V)\./I(LB value = 169 HLB value = 96 C, IIH,,0(CH,C)120)tocH2cH
cH! (■) 1 (LB value = 62 [Comparative Example 3] In Example 1, the compound represented by formula (■) shown in Table 1 was added in an amount of L instead of the compound represented by formula ([1)]. A copolymer was obtained in the same manner except for the thickness, and this was used as polymer A and subjected to cone formation in the same manner as in Example 1 to obtain a nonwoven fabric f2.

I measured the water absorption performance and it was low and n0C. )
14.0(C1(,CI(,0)8CLCIIC1l.

XO1) HLB value = 1.3 0 Comparative Example 4] In Example 1, a compound represented by formula ([X)] was used instead of the compound represented by formula (II) as shown in Table 1, and only the amount of f was A copolymer was obtained in the same manner except for the addition of
This was used as polymer A and fiberized in the same manner as in Example 1 to obtain a nonwoven fabric.

CH3o(CHyCHtO)socHycHcHt\/a ([X) HLB value = 242 Copolymerizability is insufficient and copolymerization component from nonwoven fabric. Elution of the expected compound was observed.

In addition, single fiber breakage occurred, which was thought to be due to heat resistance during spinning, and the fiberization process performance was slightly inferior.

"Comparison ρj52 60% by weight of L compound units used in Example 1 was copolymerized f
Fiberization was carried out in the same manner as in Example I using Nivolimer as polymer A. However, single filament breakage and yarn breakage occurred during spinning, and the fiberization process was poor, so it could not be evaluated as a nonwoven fabric. Ta.

[Examples 10 to 14] Examples 10 and 11 show that in Example 1, A polymer and B polymer
In Example 12, the compound ratio of the polymer was changed, and the same compound represented by the formula (II) as in Example 1 was added to polybutylene terephthalate in an amount of 1 colloid shown in Table 1 under conventional polymerization conditions. A copolymerized polymer was obtained, and this was used as polymer A and fiberized in the same manner as in Example 1 to obtain a nonwoven fabric. In Example 13, a compound represented by formula (II) was added to polyhexamethylene terephthalate under conventional polymerization conditions to obtain a copolymer, and this was used as polymer A in Example 1.
Fiberization was performed in the same manner as above to obtain a nonwoven fabric f2. Example I4 was carried out using nylon I2 as the B polymer, and one test was carried out in the same manner as in Example 1. Eventually, we will be able to obtain a nonwoven fabric that has a soft texture, good durability, and good water absorption.

Example 154 75 parts of W & Usui with a fineness of 2 denier in Example 1, 25 parts of thermal binder fiber with a fineness of 3-F: Nyl of core-sheath type composite fiber whose core component is polyethylene terephthalate and whose sheath component is an ester copolymer A fiber web with an average basis weight of 25 g/m' was obtained by passing it through a random univer, and high-pressure water jet treatment was performed on the support in the same manner as in Example 1 to obtain an apparent density of 0.28.
g/cm3:') A container for making fiber-entangled nonwoven fabric. Next,
A water stream is applied to the nonwoven fabric, and the dense side is pressed against a heated calender surface at 135°C to smooth it and bond the fibers together by melting the binder fibers. The obtained R2 non-woven fabric is suitable as a material for sanitary napkins.

Moreover, it has good water absorption performance.

- Comparative Example 6.7 In Comparative Example 6, the A/B composite ratio was 10. /90, comparative example 7
The composite ratio of A, /H was set to 90/10, and the same method as in Example 1 was used except for the method. Teaa f
two.

2 Practical Example I6 In Example 16, the same A polymer and B polymer as in Example 1 were used, and the nonwoven fabric was fabricated in the same manner as in Example 11 FIj +, except that ma was changed as shown in the cross-sectional shape of Fig. 2 (A). Obtained. Table 1 shows the measurement results of the wicking length of the fuen cloth.

The non-woven fabric has good water absorption properties and is durable.

The following margins (effects of the present invention) The present invention consists of a copolymerized polyester (A polymer) obtained by copolymerizing a predetermined amount of a compound represented by the following general formula (1) under specific conditions, and a thermoplastic polyamide (B). It is a nonwoven fabric made of composite fibers made of at least two types of polymers (polymer), and at least a portion of which has a cross-sectional shape that is easy to split, and the fibers on the surface side are split to become fine fibers. , and due to the fine structure, or the fine entanglement of the fine fibers and the undivided fibers,
The present invention provides a nonwoven fabric having flat and ffm surfaces, high strength, flexible drapability, and excellent water absorption performance.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view schematically showing the cross section of the nonwoven fabric of the present invention. It is a non-woven fabric,
FIGS. 2(a) to (+1) are representative cross-sectional views of the fibers constituting the nonwoven fabric of the present invention, and FIG. 3 is a perspective view showing the state of the fibers separated and split by the entanglement process. l: Non-woven fabric 2, densely entangled r two fiber layers 3, coarse exchange fiber #I eyebrow 4.4. Fine fiber component 5, undivided fiber portion 6.79 divided and split fine fibers Patent applicant RiRa Shi Co., Ltd.

Claims (1)

[Claims] 1. Mainly dicarboxylic acid units, diol units, and general formulas ▲ Numerical formulas, chemical formulas, tables, etc. ▼ (I) [In the formula, x and y each represent 0 or 1, and Z is the formula -O-(R_2-O) _n-R_1 (wherein R_1 represents a hydrocarbon group having 3 to 18 carbon atoms,
R_2 represents an alkylene group, and n represents the average degree of polymerization 1
5 to 29) and the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ H. L. B. Represents a monovalent group having a value within the range of 5.0 or more], and the content of the structural unit represented by the general formula (I) is 1 to 50% by weight, and 30 in a mixed solvent of equal weight of phenol and tetrachloroethane.
consisting of at least two incompatible thermoplastic polymers, copolymerized polyester (A) and thermoplastic polyamide (B), having an intrinsic viscosity of 0.5 to 1.5 dl/g at °C,
A nonwoven fabric mainly composed of composite fibers having a weight ratio of (A)/(B) of 85/15 to 15/85, wherein at least one type of polymer of the composite fibers has a fine fiber-forming property. At least a portion of each fine fiber-forming component has a different cross-sectional shape, and at least one side of the nonwoven fabric includes fine fibers formed by splitting at least a portion of the fibers or unsplit fibers. A nonwoven fabric with fiber layers intertwined with.