JP6038539B2 - Lightweight and highly deodorant nonwoven structure - Google Patents

Description

  The present invention relates to a highly deodorized nonwoven fabric structure. More specifically, the wet-heat-adhesive fiber keeps the fiber bond almost uniformly along the thickness direction, so that it has low density, light weight, high hardness and excellent without adding chemical binders or special chemicals. The present invention relates to a nonwoven fabric structure having high deodorizing performance. In particular, a flame retardant board containing a flame retardant in the highly deodorized nonwoven fabric structure of the present invention is useful as a building material board.

  General uses of non-woven fabric with deodorizing function include car floor carpets, paper sliding doors, wallpaper, cushions, cushions, bed mats, various pet equipment, blinds, non-woven curtains, various carpets, artificial flower materials, non-woven table cloths, various types Sheets (hospital, nursing, etc.), blankets, duvet covers, pillow covers, bed covers, bedding, toilet seat covers, wiping cloth, satellite materials, various filters, humidifier filters, various interior materials (sound absorbing materials, sound absorbing panels, It is used in general where other non-woven fabrics such as partitions, partitions, etc.) and boards for building materials are used. In addition, certain of them are required to be flame retardant from the awareness of disaster prevention.

In our daily life, there are many applications and supplies that are expected to improve convenience, comfort, hygiene, etc. due to the deodorizing function. Since the fiber has a large surface area, the fiber itself has a deodorizing function, so it is expected that its deodorizing performance will be higher than that of films and plastics, and it can be applied to many textile products such as woven and knitted fabrics, non-woven fabrics, and paper. There is a merit that is.
As a method of imparting a deodorizing function to the fiber, the fine particles of the deodorizing agent are kneaded into the fiber-forming resin and spun, or the fine particles of the agent are applied and adhered to the above-mentioned various fiber products together with the binder resin for adhesion. In the case of a thermoplastic fiber, the fiber surface is heated to a state close to a molten state, and the drug fine particles are attached only to the fiber surface, or the heated drug fine particles are attached to the fiber surface by spraying. It has been known. For example, in Patent Document 1, an attempt is made to impart a function by incorporating a deodorizing agent into ethylene-vinyl alcohol disposed in a part of the fiber to form a fiber. However, in the method of Patent Document 1, the amount of the drug embedded in the fiber resin is large, and the deodorizing performance is lowered as compared with the content of the drug in the fiber. Further, although a device has been devised to avoid gelation of the resin during spinning in the state of inclusion in the ethylene-vinyl alcohol resin, it is still difficult to control spinning and a high technique is required. In addition, when the chemical is attached and processed with a resin binder, as is well known, if the chemical is processed in a large amount in order to avoid dropping of the chemical, the chemical is buried in the binder and the deodorizing function is lowered. In addition, the processing of a large amount of resin causes a problem that the texture of the fabric after processing becomes hard. If the amount of binder used to avoid these problems is reduced, the above-mentioned problems will be solved, but the drug will easily drop off, and it will drop off during use and washing, and the deodorizing function will last longer. I will not.

  In order to eliminate the above-described drawbacks, a method has been proposed in which drug particles are heated and brought into contact with the fiber surface in a high temperature state without using a binder resin, and the particles are supported and fixed by fusing the fiber surface. (For example, refer to Patent Document 2). Compared with the method in which the drug particles are bonded with a binder or the like in the method of Patent Document 2, the drug is completely exposed and a large number of drugs are fixed to the fiber surface, so that the fixed drug can efficiently function. However, the sticking state tends to be uneven, and the drug is likely to fall off during use. In addition, since a large amount of hard drug particles are exposed on the fiber surface, the surface texture of the fabric made from the fiber feels rough, and when it touches or rubs other things, There is a possibility of hurting the other object. Accordingly, usable scenes are limited.

  Further, as deodorizing agents, those that exhibit a deodorizing function by photocatalytic action are known (see, for example, Patent Documents 3 to 4), but these functions are expressed in the presence of light, and the use scene is limited. Is done.

JP-A-10-219520 JP 2009-174114 A Japanese Patent Application Laid-Open No. 08-284011 JP 2004-169217 A

  The present invention can be easily broken or broken even if a force exceeding the maximum bending stress is applied, while having a low density, light weight and high bending stress, without using a special drug or the like. An object of the present invention is to provide a non-woven fabric structure having a hard and excellent deodorizing function.

As a result of intensive studies to solve the above problems, the present inventors have reached the present invention.
That is, in the present invention, 75 mol% or more of the dicarboxylic acid component is terephthalic acid and / or an ester-forming derivative thereof, and the compound (i) represented by the following formula (I) as the copolymerization component is further represented as (ii): Cyclohexadicarboxylic acid and / or its ester-forming derivative, (iii) is a fiber in which a polyester (A) comprising a fatty acid and its ester-forming derivative is partially exposed on the surface, and other components are wet heat adhesive It is a nonwoven fabric structure composed of a composite fiber composed of a polymer (B) and having a structure in which the fibers are slightly fused, preferably containing 20 to 100% by mass of the composite fiber, and 0.05 to 0.5 g. / Cm ³ non-woven fabric structure having a bending stress of at least 0.05 MPa in at least one direction and a correlation between bending stress and displacement In this regard, the nonwoven fabric structure is characterized in that a stress of 1/10 or more of the bending stress peak value is maintained even at a displacement twice as large as the bending stress peak.

  According to the present invention, it has low density, light weight and high hardness, absorbs the stress by bending and deforming the applied stress, and easily breaks or breaks even if a strong impact is applied. A non-woven fabric structure having an excellent deodorizing function can be provided at low cost.

  The non-woven fabric structure having an excellent deodorizing function of the present invention has a "bending behavior" and "lightness" that cannot be obtained with a normal non-woven fabric by setting the arrangement of the constituent fibers and the bonding state between the fibers within a predetermined range. ", And it is more difficult to break, and shape retention and air permeability are secured at the same time.

  Such a nonwoven fabric structure having an excellent deodorizing function is obtained by causing superheated steam to act on a web using wet heat adhesive fibers as raw material fibers, so that each fiber is below the melting point when drying the adhesive resin. The fibers can be obtained by wet-heat bonding so as to form a “scrum” at a temperature of 5 ° C., so that the intended bending behavior, light weight and air permeability can be realized.

  In the conjugate fiber of the present invention, the polyester resin used for the component A contains a metal salt (i) of sulfoisophthalic acid represented by the following chemical formula (I) as a copolymerization component as one of the copolymerization components. It is a copolyester containing a metal salt (i) of isophthalic acid.

Examples of the metal salt (i) of sulfoisophthalic acid represented by the above formula (I) include 5-sodium sulfoisophthalic acid, or sulfonic acid alkali metal bases such as 5-potassium sulfoisophthalic acid and 5-lithium sulfoisophthalic acid. And dicarboxylic acid component having 5-tetraalkylphosphonium sulfoisophthalic acid such as 5-tetrabutylphosphonium sulfoisophthalic acid and 5-ethyltributylphosphonium sulfoisophthalic acid.
Only one type of the metal salt (i) of sulfoisophthalic acid represented by the above formula (I) may be copolymerized in the polyester, or two or more types may be copolymerized.
By copolymerizing the metal salt (i) of sulfoisophthalic acid represented by the above formula (I), an amorphous part can be retained in the fiber internal structure as compared with the conventional polyester fiber, and the B component described later The composite fiber that is combined with the material combines excellent crimpability and stress characteristics.

  The copolymerization amount of the metal salt (i) of sulfoisophthalic acid represented by the above formula (I) is preferably 1.0 mol% to 3.5 mol%. When the copolymerization amount of (i) is less than 1.0 mol%, the deodorizing performance intended by the present invention may not be obtained when a composite fiber is obtained. On the other hand, when the copolymerization amount of (i) exceeds 3.5 mol%, the viscosity of the polyester becomes remarkable and spinning becomes difficult. From the standpoint of deodorizing performance and spinnability, the copolymerization amount of (A) is preferably 1.2 to 3.0 mol%, more preferably 1.5 to 2.5 mol%.

  Further, in the component A, the dicarboxylic acid component other than the above (i) in the component A is 2.0 to 10.0 mol% of cyclohexanedicarboxylic acid and / or its ester-forming derivative (ii), preferably 5. 0 to 10.0 mol%, and aliphatic dicarboxylic acid and / or ester-forming derivative thereof is 2.0 to 8.0 mol%, preferably 3.0 to 6.0 mol%. preferable. When the copolymerization amount of (ii) is less than 2.0 mol%, the intended hardness of the present invention may not be obtained when a nonwoven fabric structure is obtained. On the other hand, when the copolymerization amount of (ii) exceeds 10.0 mol%, when the yarn is produced by a high-speed spinning method without stretching, the glass transition temperature of the resin is low and the orientation of the amorphous part inside the fiber Due to the low degree, it is not possible to obtain stable high-speed stringiness due to stable fiber properties and spontaneous elongation during high-speed winding.

  The cyclohexanedicarboxylic acid used in the present invention includes three positional isomers of 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid. From the point obtained, any positional isomer may be copolymerized, or a plurality of positional isomers may be copolymerized. Further, although there are cis / trans isomers for each positional isomer, any stereoisomer may be copolymerized, or both cis / trans positional isomers may be copolymerized. The same applies to the cyclohexanedicarboxylic acid derivative.

  As for the fatty acid dicarboxylic acid and its ester-forming derivative component, similarly to the cyclohexynedicarboxylic acid component, the crystal structure of the polyester fiber is disturbed, and the orientation of the amorphous part is lowered. The fiber combines excellent crimpability and stress properties.

  The copolymerization amount of the fatty acid component in the dicarboxylic acid component is preferably 2.0 mol% to 8.0 mol%. When the copolymerization amount is less than 2.0 mol%, the intended hardness of the present invention may not be obtained when a nonwoven fabric structure is obtained. When the copolymerization amount of the fatty acid component in the dicarboxylic acid component exceeds 8.0 mol%, when the yarn is produced by a high-speed spinning method without stretching, the degree of orientation of the amorphous part in the fiber is low, Stable high-speed spinnability cannot be obtained due to stable fiber properties and remarkable spontaneous elongation during high-speed winding. More preferably, it is 3.0 mol%-7.0 mol%.

  Preferred examples of the aliphatic dicarboxylic acid component of the present invention include aliphatic dicarboxylic acids such as adipic acid, sebacic acid and decanedicarboxylic acid. These can be used alone or in combination of two or more.

Further, the polyester resin constituting the component A of the present invention includes a matting agent such as titanium oxide, barium sulfate, and zinc sulfide, a heat stabilizer such as phosphoric acid and phosphorous acid, a light stabilizer, and an antioxidant. Agents, surface treatment agents such as silicon oxide, and the like may be included as additives. By using silicon oxide, the resulting fiber can impart fine irregularities to the fiber surface after weight reduction processing, and darkening is realized when it is later made into a woven or knitted fabric. Furthermore, thermal decomposition during heat melting or subsequent heat treatment can be suppressed by using a heat stabilizer. Moreover, the light resistance at the time of use of a fiber can be improved by using a light stabilizer, and it is also possible to improve dyeability by using a surface treating agent.
Moreover, it is preferable that the intrinsic viscosity of resin which comprises A component is 0.55-0.70.

  The resin constituting the wet heat adhesive fiber used for the component B of the composite fiber of the present invention is preferably a resin component that softens with hot water at about 95 to 100 ° C. and adheres to itself or adheres to other fibers. And the like, polylactic acid, ethylene-vinyl alcohol copolymer and the like. Also included are polyurethane-based, polyolefin-based, polyester-based, polyamide-based, styrene-based elastomer resins, etc., that can flow or easily deform at a temperature that can be easily realized by superheated steam and exhibit an adhesive function. Among these, an ethylene-vinyl alcohol copolymer can be particularly preferably used.

  Here, as the ethylene-vinyl alcohol copolymer preferably used as the wet heat adhesive fiber or wet heat adhesive component, a copolymer obtained by copolymerizing 10 to 60 mol% of ethylene units with polyvinyl alcohol is used. In particular, a copolymer obtained by copolymerizing 30 to 50 mol% of ethylene units is preferable for ensuring the processability of the nonwoven fabric. The vinyl alcohol portion preferably has a saponification degree of 95 mol% or more. Due to the large number of ethylene units, a unique property of having wet heat adhesiveness but not hot water solubility is obtained. The degree of polymerization can be selected as necessary, but is usually about 400 to 1500.

  When the ethylene unit content is less than 10 mol%, the ethylene-vinyl alcohol copolymer easily swells and gels with low-temperature water, and the form may change once wetted with water. On the other hand, if it exceeds 60 mol%, the hygroscopicity is lowered and fiber fusion due to wet heat becomes difficult to develop, so that practical hardness may not be ensured.

The composite fiber of the present invention is not particularly limited in the composite form as long as a part or all of the wet heat adhesive resin is continuously present in the length direction on the fiber surface. For example, a core-sheath type, a sea-island type, a side-by-side type, a multilayer bonding type, a random composite, a radial bonding type, and the like can be given. Or the fiber which coat | covered the resin which has wet heat adhesiveness to the fiber which consists of another fiber-forming polymer may be sufficient.
For example, it may have a cross-sectional structure as shown in FIG.

  In addition, when the mass ratio of the wet heat adhesive resin constituting the fiber exceeds 90, the composite fiber of the present invention cannot maintain the form of the fiber with other resins, and sufficiently secures the strength of the composite fiber itself. It becomes difficult. On the other hand, if the mass ratio of the wet heat adhesive resin is less than 10, the amount of the wet heat adhesive resin is so small that the resin layer cannot hold the fiber form, and a continuous resin layer in the length direction is held. This ratio is extremely difficult, and at this ratio, sufficient fiber bond strength cannot be secured. This is the same when the wet heat adhesive resin is coated on the fiber.

   The method for producing the conjugate fiber of the present invention is not particularly limited as long as the conjugate fiber satisfying the provisions of the present invention is obtained. When a composite flow of polyester (A) and ethylene-vinyl alcohol copolymer (B) is introduced into the nozzle inlet using a composite spinning device, the number of pores corresponding to the number of protrusions made of polyester (A) The polyester (A) is allowed to flow from the flow dividing plate provided on the circumference, and then the entire flow of the copolymer polyester (A) flowing from the respective pores is covered with the ethylene-vinyl alcohol copolymer (B). However, it can be manufactured by introducing the composite flow toward the center of the nozzle inlet and melting and discharging from the nozzle. Further, in order to ensure the quality required for the final product and good processability, an optimum spinning / drawing method can be selected. More specifically, a spin draw method or a 2-step method in which a spinning raw yarn is collected and then drawn in a separate process may be employed. Further, even in a method in which the undrawn yarn is not drawn and the take-up speed is taken up at a speed of 2000 m / min or more, the composite fiber of the present invention can be obtained by commercializing the yarn after passing through any yarn processing step. Can do.

  Next, the composite fiber having such wet heat adhesiveness and high deodorizing performance is formed into a web and the fiber is fixed to obtain a desired hard nonwoven fabric structure. Regarding the web formation, the spunbond method, the melt blow method Alternatively, the web may be formed using a dry method such as a card method or an air lay method using staple fibers. As the staple fiber web, a random web, a semi-random web, a parallel web, a cross wrap web or the like is preferably used.

  When manufacturing such a fiber web, other fibers may be mixed as necessary. In this case, the mixing ratio of the composite fiber of the present invention is 20% by mass or more, preferably 50% by mass or more. More preferably, it is 70 mass% or more. The higher the ratio of wet heat adhesive fibers, the easier it is to finish a hard nonwoven fabric. When this fiber is less than 20% by mass, it is not only impossible to ensure sufficient hardness, but also it becomes difficult to maintain the handleability as a nonwoven fabric.

In order to obtain a hard nonwoven fabric having a well-balanced bending hardness and light weight as the object of the present invention from the fiber web, it is necessary to appropriately adjust the arrangement state and adhesion state of the fibers constituting the nonwoven fabric. That is, it is important that the constituent fibers are arranged substantially parallel to the surface of the nonwoven fabric (sheet) and that these fibers are bonded to each other at their intersections as much as possible. In particular, it is desirable that the fibers have a structure in which “scrums” are assembled, and such a structure is uniformly distributed along the thickness direction. This is because if there are many fibers oriented along the thickness direction (perpendicular to the sheet surface), the fiber arrangement is disturbed in the periphery, creating unnecessary voids in the nonwoven fabric, and reducing the hardness of the nonwoven fabric. Because it will end up. Therefore, it is necessary to reduce this gap as much as possible. For this purpose, it is desirable to arrange the fibers as parallel as possible to the sheet surface.
In addition, the term “almost parallel to the sheet surface” as used herein means that there are repeated portions where a large number of fibers are locally arranged along the thickness direction, such as a needle punched nonwoven fabric. Indicates a state where there is no such thing. More specifically, it refers to a state in which, when an arbitrary cross section of the nonwoven fabric is observed with a microscope, the existing ratio of fibers continuously extending over 30% or more of the thickness is 10% or less.

Furthermore, these constituent fibers are bonded at their respective contacts, but in order to develop a large bending stress with as few contacts as possible, this bonding point extends from the nonwoven fabric surface to the center and the opposite surface. It is preferable that it is uniformly distributed along the thickness direction. If the adhesion points are concentrated on the surface or the center, it is difficult not only to secure a sufficient bending stress, but also there is a high possibility that the form stability at a place where the adhesion points are small is insufficient.
Therefore, in the hard nonwoven fabric of the present invention, when the cross section of the nonwoven fabric is divided into three equal parts along the thickness direction, the fiber adhesion rate in each of the three divided regions is 85% or less, and the fiber adhesion The difference between the maximum value and the minimum value of the rate is preferably 20% or less. The fiber adhesion rate is more preferably 5 to 60%, and still more preferably 10 to 35%. Further, the difference between the maximum value and the minimum value of the adhesion rate is more preferably 15% or less, and further preferably 10% or less. In addition, the fiber adhesion rate said to this invention is measured by the method mentioned later.

  The non-woven fabric structure of the present invention has a board-like form unlike a normal non-woven fabric, and one of the major features is that it exhibits a bending behavior that cannot be obtained with a normal non-woven fabric. In the present invention, in order to represent this bending behavior, the maximum stress (peak stress) when the repulsive force of the sample generated when the sample is gradually bent is measured according to JIS K7017 “Fiber-reinforced plastics—How to obtain bending characteristics”. ) As a bending stress. That is, it can be said that the larger the bending stress, the harder the structure. Moreover, it can be said that it is a structure which bends well, so that the bending amount (displacement) until the structure used as a measuring object breaks is large. The nonwoven fabric structure of the present invention has a bending stress in at least one direction of 0.05 MPa or more, preferably 0.1 MPa to 30 MPa, and more preferably 0.2 MPa to 20 MPa. When this bending stress is less than 0.5 MPa, it is easily broken by its own weight when used as a board material, so that the body as a board material is not formed. On the other hand, if it exceeds 30 MPa, it becomes too hard, and it is not preferable because when it is bent, if it bends beyond the peak of bending stress, it will break and break.

  Looking at the correlation between this amount of bending (displacement) and the resulting bending stress, initially, the stress increases as the amount of bending increases. In the nonwoven fabric structure of the present invention, when the bending amount inherent to the measurement sample is reached, the stress gradually decreases thereafter. That is, it shows a correlation that draws an upwardly convex parabolic curve. One feature of the nonwoven fabric structure of the present invention is that it has a so-called “stickiness” without causing a rapid stress drop even when it is attempted to bend beyond the peak of the bending stress. As an index representing such “stickiness”, the present inventors used the bending stress remaining in the state exceeding the displacement at the peak of the bending stress. That is, in the nonwoven fabric structure of the present invention, the stress when bending to a displacement twice the displacement showing the peak of the bending stress (hereinafter sometimes expressed as “double displacement stress”) has a peak stress value. 1/10 or more is maintained, preferably 3/10 or more, more preferably 5/10 or more.

  The hard nonwoven fabric structure of this invention can ensure the outstanding lightweight property by the space | gap which arises between constituent fibers. In addition, unlike the resin foam such as sponge, these voids are not independent but continuous, and thus have air permeability. Such a structure is extremely difficult to manufacture by the conventional method of hardening a non-woven fabric that is impregnated with a resin or forming a film-like structure by closely bonding the surface of the non-woven fabric. It is.

From such a viewpoint, the nonwoven fabric structure of the present invention has a density of 0.05 to 0.5 g / cm ³ , preferably 0.08 to 0.4 g / cm ³ , and more preferably. 0.10 to 0.35 g / cm ³ . If the density is less than 0.05 g / cm ³ , it is lightweight, but it is difficult to ensure sufficient bending hardness. Conversely, if it exceeds 0.5 g / cm ³ , the hardness can be sufficiently secured. However, it is difficult to say that the nonwoven fabric is lightweight.
Also, the basis weight of the nonwoven structure of the present invention is preferably in the range of 50~10000g / ^{m 2,} more preferably 150~8000g / ^{m 2,} more preferably from 300~6000g / ^{m 2.} If the basis weight is less than 50 g / m ^2, it is difficult to secure the hardness, also the basis weight is more than 10000 g / m ^2, and the web is too thick, not superheated steam impenetrable sufficiently to the web inside, It may be difficult to obtain a uniform structure in the thickness direction. On the other hand, the thickness is preferably in the range of 1 to 100 mm, more preferably 3 to 50 mm, and even more preferably 5 to 30 mm. If the thickness is less than 1 mm, it is difficult to ensure the hardness. If the thickness exceeds 100 mm, the mass becomes heavy, which is not preferable because the handleability is lowered.

Furthermore, for example, in the case of a case where a decorative film is pasted when used as a board material, the film floats after the film is pasted due to the air in the film escapes to the opposite side due to the air permeability of the nonwoven fabric structure of the present invention. There is a merit that peeling can be avoided. In addition, there is an advantage that strong adhesion can be realized by sticking the adhesive of the attached film to the constituent fibers on the surface and entering the fiber gap like a wedge. Furthermore, by using such a board, it is possible to exchange air inside and outside the container, and it can be applied to a wide range of uses, such as being applicable to a breathing organism or a container for transporting a substance.
The air permeability is preferably 0.1 cm ³ / cm ² / sec or more, more preferably 1 to 250 cm ³ / cm ² / sec, and most preferably 5 to 200 cm in terms of air permeability according to the Frazier method. ³ / cm ² / sec. When the air permeability is less than 0.1 cm ³ / cm ² / sec, it is necessary to apply pressure from the outside in order for air to pass through the nonwoven fabric, and natural air cannot enter and exit, which is not preferable. On the other hand, if the air permeability exceeds 250 cm ³ / cm ² / sec, the air permeability becomes high, but the fiber voids in the nonwoven fabric become too large, and there are cases where sufficient bending stress cannot be secured, which is not preferable.

  In addition to this, the nonwoven fabric structure of the present invention also has good shape retention by having the fiber bonding points uniformly in the thickness direction as described above. In other words, even with a normal nonwoven fabric, even if the required bending hardness can be ensured by a binder or the like, basically there is little adhesion between the fibers. For example, when cut into small pieces of about 5 mm square, the nonwoven fabric can be removed with a slight external force. The constituent fibers are detached and eventually fall apart. On the other hand, since the hard nonwoven fabric of the present invention has the fibers closely and uniformly bonded to each other, even when the fibers are cut into small pieces, the fibers do not fall apart and can sufficiently retain the form.

In the nonwoven fabric structure excellent in the deodorizing function of the present invention, the constituent fibers themselves have deodorizing properties, and the fiber surface is exposed because the resin binder or the like is not used. In addition, the nonwoven fabric structure is fixed at the fusion point between the fibers, and can be made into a bulky structure. Air can easily enter and exit the structure. For this reason, odors can easily enter the structure, and the entire fiber constituting the structure can exhibit a deodorizing action. The deodorization performance is greatly influenced by the surface area of the fiber. A preferable fineness can be selected from a range of about 0.01 to 100 dtex, preferably 0.1 to 50 dtex, more preferably 0.5 to 30 dtex (particularly 1 to 10 dtex). When the fineness is within this range, the object of the present invention can be satisfied in a balanced manner. If the fineness is too thin, the surface area effect of the fiber will increase, but the structure will be too dense and it will be difficult to perform the deodorizing function of the internal fiber, and if the fineness is too large, the surface area of the fiber will decrease and deodorizing Sexuality gets worse.
Further, since it is constituted by a very large number of fine fusions between fibers, it has excellent deformation resistance and flexibility. For this reason, even if a force such as compression is applied because the structure is hard to collapse, the structure is easily restored when the pressure is released, and the fiber surface inside the structure is the side of adjacent fibers. There is no overlap, the exposed effective fiber surface is always maintained, and the deodorizing function is exhibited.

Next, the manufacturing method of the nonwoven fabric structure of this invention is demonstrated.
The fiber web formed by the above-described method is sent to the next process by a belt conveyor, and then exposed to a superheated steam (high-pressure steam) stream to obtain the hard nonwoven fabric of the present invention. The belt conveyor used here is not particularly limited as long as it can basically transport the fiber web used for processing without disturbing its form, but an endless conveyor is preferably used. Of course, a general single belt conveyor may be used, or another belt conveyor may be prepared as necessary, and a web may be sandwiched between the two conveyors. In this way, when the web is processed, it is possible to suppress deformation of the form of the web that has been transported by an external force such as water, superheated steam, or conveyor vibration used for the processing. It is also possible to control the density and thickness of the processed nonwoven fabric by adjusting the distance between the belts.

A steam injection device for supplying steam to the web is mounted in one conveyor and supplies steam to the web through a conveyor net. A suction box may be attached to the opposite conveyor. In this case, excess steam that has passed through the web can be sucked and discharged. Furthermore, in order to steam the front and back of the web at the same time, a suction box is installed on the downstream side of the conveyor where the steam injection device was installed, and a steam injection device is installed in the opposite conveyor May be. If there is no steam injection device and suction box in the downstream portion, if the front and back of the nonwoven fabric are to be steamed, it can be substituted by reversing the front and back of the nonwoven fabric once treated and passing through the processing device again.

  The endless belt used for the conveyor is not particularly limited as long as it does not hinder the conveyance of the web or the superheated steam treatment. However, when the superheated steam treatment is performed, the surface shape of the belt may be transferred to the nonwoven fabric surface depending on the conditions. In particular, when it is desired to obtain a nonwoven fabric having a flat surface, a net with fine mesh may be used. In this case, the upper limit is about 90 mesh. A finer mesh than this is not preferable because the air permeability is low and it is difficult for superheated steam to pass through. The belt material is preferably a mesh belt made of metal, heat-treated polyester, polyphenylene sulfide, or heat-resistant resin such as polyarylate or wholly aromatic polyester from the viewpoint of heat resistance against steam treatment.

Next, the web is conveyed by a conveyor, and when passing through a high-speed superheated steam flow ejected from a nozzle, the fibers are three-dimensionally bonded to each other by the sprayed superheated steam.
Since this superheated steam is an air stream, the fibers in the web, which is the object to be treated, enter the inside of the web without being largely moved (as in the water entanglement process or the needle punch process). It is considered that the vapor flow intrusion action into the web and the moist heat action effectively cover the surface of each fiber existing in the web in a moist heat state to enable uniform thermal bonding. In addition, since this treatment is performed in a very short time under a high-speed air flow, the heat conduction to the fiber surface is fast, but the heat conduction to the inside of the fiber is not so fast. It is also difficult to cause deformation that damages the thickness of the web itself. As a result, wet-heat bonding is performed so that the degree of bonding in the surface and thickness direction is substantially uniform without crushing the web.
At this time, if the back side of the endless belt on the opposite side of the nozzle across the web is made of a stainless steel plate or the like so that the vapor cannot pass, the vapor that has passed through the web that is the object to be treated is reflected here, It is more firmly bonded by the heat retaining effect. On the other hand, when light adhesion is necessary, a suction box may be arranged to discharge excess water vapor to the outside.

The nozzle for injecting the water vapor may be a plate or die in which predetermined orifices are continuously arranged in the width direction, and may be arranged so that the orifices are arranged in the width direction of the web to be supplied. At this time, one or more orifice rows may be provided, and a plurality of rows may be arranged in parallel. Of course, a plurality of nozzle dies having a single orifice array may be installed in parallel.
For example, when using a type of nozzle in which an orifice is formed in a plate, the thickness of the plate is mainly about 0.5 to 1.0 mm. In this case, the diameter and pitch of the orifice are not particularly limited as long as the target fiber can be fixed, but usually, those having a diameter of 0.05 to 2.0 mm are often used. Is 0.1 to 1.0 mm, more preferably 0.2 to 0.5 mm. On the other hand, the pitch of the orifices is usually 0.5 to 3.0 mm in many cases, but is preferably 1.0 to 2.5 mm, more preferably 1.0 to 1.5 mm.
When the diameter of the orifice is smaller than 0.05 mm, it is preferable because the processing accuracy of the nozzle is lowered and the processing is difficult, and the operational problem is that clogging is likely to occur. Absent. On the contrary, when it exceeds 2.0 mm, it is difficult to obtain a sufficient water vapor injection force, which is not preferable. On the other hand, when the pitch is less than 0.5 mm, the nozzle holes are too dense, which is not preferable because the strength of the nozzle itself is reduced. On the other hand, when the pitch exceeds 3 mm, there are cases where the superheated steam does not sufficiently hit the web, and it may be difficult to ensure sufficient web strength.

Also, the superheated steam used for fiber bonding is not particularly limited as long as the target fiber fixation can be realized, and may be set depending on the material and form of the fiber used, but steam of 0.1 MPa to 2.0 MPa is used. It is preferably used, more preferably 0.2 to 1.5 MPa, and still more preferably 0.3 to 1.0 MPa. For example, if the steam pressure is too high or too strong, the fibers that form the web will move, causing turbulence, or the fibers will melt too much to partially retain the fiber shape. May cause problems.
In addition, when the pressure is too weak, it becomes impossible to give the heat necessary for fiber fusion to the object to be processed, or water vapor cannot penetrate the web, and fiber fusion spots are generated in the thickness direction. And problems such as difficulty in controlling the uniform ejection of vapor from the nozzles are likely to occur.

If necessary, it is also possible to give a design to a product obtained by giving a predetermined uneven pattern, characters, pictures, etc. to the conveyor belt and transferring them.
Further, it can be laminated with other materials or formed into a desired form by molding.

  After the fibers of the fiber web are partially wet-heat bonded in this way, moisture may remain on the nonwoven fabric, and the web must be dried as necessary. Regarding the drying, it is necessary that the nonwoven fabric surface in contact with the heating body for drying maintain the fiber form without forming a film after drying, and any method can be used as long as this can be achieved. Therefore, you may use a large drying facility such as a cylinder dryer or tenter that has been used for drying nonwoven fabrics in the past. When the level is dryable by means, a non-contact method such as far-infrared irradiation, microwave irradiation, or electron beam irradiation, or a method of blowing hot air is preferred.

  In addition, when such a nonwoven fabric structure is used as, for example, an automobile interior material, an aircraft inner wall material, or a building material, flame retardancy may be required. In such a case, flame retardancy can be secured by adding a flame retardant as usual. In particular, it is preferable to use a boron-based and / or silicon-based flame retardant as the flame retardant because the nonwoven fabric structure of the present invention exhibits excellent flame retardancy.

Examples of the boron-based flame retardant include boric acid such as orthoboric acid and metaboric acid, borax, sodium borate obtained therefrom, and a flame retardant containing at least one component thereof.
On the other hand, examples of the silicon-based flame retardant include a flame retardant containing polyorganosiloxane represented by silicone, organic silicate, silica and the like.

  Among these, in the present invention, a flame retardant mainly composed of boric acid and borax is preferable. In particular, it is preferable to add 10 to 35 parts by mass of boric acid and 15 to 45 parts by mass of borax with respect to 100 parts by mass of water, and to process using a flame retardant comprising a dissolved aqueous solution.

  As a method for flame retardancy, a method of impregnating or spraying a non-woven structure of the present invention with an aqueous solution or emulsion of a flame retardant and drying the same as in a normal dip-nip process, or a twin-screw extruder during fiber spinning It is possible to use a production method in which a resin kneaded with a flame retardant is extruded and spun, and this yarn is used to form a nonwoven fabric.

  The amount of the flame retardant to be used is not particularly limited as long as the desired flame retardant effect can be obtained. In the case of the nonwoven fabric structure of the present invention, about 1 to 15% by mass with respect to the mass of the nonwoven fabric is in terms of cost and performance. To preferred.

  By processing with these flame retardants, it is possible to impart extremely excellent flame retardancy to the nonwoven fabric structure of the present invention, as well as problems with other flame retardants, such as halogen gas during combustion in the case of halogens The effect of avoiding problems such as acid rain accompanying the outbreak and eutrophication of the lake due to the outflow of phosphorus compounds due to hydrolysis in the case of phosphorus system can also be expected. Moreover, the nonwoven fabric structure of this invention which provided the flame retardance can be utilized as a flame retardant board.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. In addition, each physical-property value in an Example was measured with the following method.

(1) Melt index (MI) of ethylene-vinyl alcohol copolymer
According to JIS K6760, it measured using the melt indexer on the conditions of 190 degreeC and a 21.2N load.

(2) Weight per unit (g / m ² )
It measured according to JIS L1913.

(3) Thickness (mm), density (g / cm ³ )
The thickness was measured according to JIS L1913, and the density was calculated from this value and the basis weight measured by the method (2).

(4) Air permeability (cm ³ / cm ² / sec)
According to JIS L1096, it measured by the fragile type method.

(5) Bending stress (MPa)
It measured according to A method (three-point bending method) among the methods as described in JIS K7017. At this time, a measurement sample having a width of 25 mm × 80 mm was used, and measurement was performed at a fulcrum distance of 50 mm and a test speed of 2 mm / min. In the present invention, the maximum stress (
The peak stress was defined as the bending stress. In addition, the bending stress measurement was performed about MD direction and CD direction. Here, the MD direction means a state in which the measurement sample is collected and measured so that the web flow direction (MD) is parallel to the long side of the measurement sample, while the CD direction is the long side of the measurement sample. A measurement sample is taken so that the web width direction (CD) is parallel to the web width direction (CD).

(6) Double displacement stress (MPa)
In the measurement of the bending stress in (5), the stress when exceeding the displacement showing the bending peak stress and continuing to bend to twice the displacement was defined as the double displacement stress.

(7) Fiber adhesion rate (%)
Using a scanning electron microscope (SEM), a photograph in which the cross section of the nonwoven fabric was magnified 100 times was taken. The photograph of the cross-section of the nonwoven fabric taken is divided into three equal parts in the thickness direction, and in each of the three divided areas (surface, center, opposite surface), the cut surface where the fibers are bonded to the number of fiber cut surfaces found there The percentage of numbers was determined.
Of the total number of fiber cross sections that can be found in each region, the ratio of the cross section in which two or more fibers are bonded is expressed as a percentage.
Fiber adhesion rate (%) = (number of cross sections of fibers bonded two or more) / (total number of cross sections of fibers) × 100
However, for each photograph, all the fibers with a visible cross section were counted, and when the number of fiber cross sections was 100 or less, a photograph to be observed was added so that the total fiber cross section exceeded 100.
In addition, the fiber adhesion rate was calculated | required about each area | region divided into 3 equally, and the difference of the maximum value and minimum value was also calculated | required together.

(8) Non-woven fabric shape retention The nonwoven fabric sample was cut into a 5 mm square cube and placed in an Erlenmeyer flask (100 cm ³ ) containing 50 cm ³ of water. A shaker (manufactured by Yamato Scientific Co., Ltd., “MK1
60 type ") and was shaken at a speed of 60 rpm for 30 minutes in a swiveling method with an amplitude of 30 mm. After shaking, the morphological change and the morphological state were visually confirmed, and a three-stage evaluation was performed.
(Double-circle): The shape before a process is substantially maintained.
○: Large missing part is not seen, but deformation of form is seen.
X: Occurrence of missing parts is observed.
Moreover, the sample after a process was collect | recovered with the 100-mesh metal-mesh, this was dried at room temperature all day and night, mass was measured, and mass retention was measured.
(9) Deodorization performance evaluation a. Initial performance Under normal incandescent fluorescent light irradiation (500 lux),
3 g of sample is sealed in a tedra bag (volume: 3 liters) that is allowed to stand at 15 cm, and then the tedra bag is filled with air containing a predetermined concentration of odor components using a syringe so that the total gas volume is 3 liters. Injected into. The injected gas was 40 ppm ammonia and 40 ppm acetic acid. After injecting the gas, the gas in the tedlar bag is sampled with a microsyringe after a lapse of a specified time, and the gas concentration of acetic acid is measured by gas chromatography (GC-7A type, manufactured by Shimadzu Corporation) to determine the odor component removal rate. It was calculated by the following formula. For ammonia, a gas detector tube (manufactured by Kitagawa Co., Ltd., ammonia type) was used to directly measure the gas concentration in the Tedlar bag and calculate the removal rate of odor components. Similarly, measurement under light shielding was also performed.
Removal rate (%) = [(C0−C) / C0] × 100
C0: initial gas concentration C: gas concentration after 1 hour b. Repeated deodorization performance Under normal incandescent fluorescent light irradiation (500 lux), 3 g of sample was placed in a Tedlar bag (volume: 3 liters) placed at a distance of 15 cm and sealed, and then a odor component with a predetermined concentration was removed using a syringe. The air contained was injected into the tedlar bag so that the total gas volume was 3 liters. The injection gas was 40 ppm acetic acid. The gas concentration one hour after the gas was injected was measured by gas chromatography, and air containing 40 ppm of acetic acid was injected into the Tedra bag. Gas concentration measurement and acetic acid injection were repeated every hour.

[Example 1]
As shown in Table 1, 88.3 mol% of the dicarboxylic acid component is terephthalic acid (TA), 1.7 mol% of 5-sodium sulfoisophthalic acid, and 1,4-cyclohexanedicarboxylic acid (CHDA). The fiber surface is made by a transesterification and polycondensation reaction between 5.0 mol% and 5.0 mol% adipic acid, each carboxylic acid component containing ethylene glycol, and certain additives. The other component is an ethylene-vinyl alcohol copolymer (ethylene content 44 mol%, saponification degree 98.4 mol%, composite ratio = 50/50). A composite staple fiber (3 dtex, 51 mm length, 21 crimps / inch, 13.5% crimp rate) having a wet-heat adhesive property having the cross-sectional structure shown in 2 was prepared.
Using the core-sheath type composite staple fiber, a web having a basis weight of about 100 g / m ² was produced by a card method, and seven sheets of this web were stacked to obtain a card web having a total basis weight of 700 g / m ² .
The card web was transferred to a belt conveyor equipped with a 50 mesh, 500 mm wide stainless steel endless wire mesh. In addition, the same metal mesh was equipped in the upper part of the metal mesh of this belt conveyor, each rotated in the same direction at the same speed, and the belt conveyor which can adjust the space | interval of these both metal meshes arbitrarily was used.
Next, the card web is introduced into a steam jetting device provided on the belt conveyor, and 0.4 MPa of superheated steam is jetted perpendicularly to the card web from the device to perform steam treatment, thereby obtaining the nonwoven fabric structure of the present invention. It was. In the steam injection device, a nozzle is installed in one conveyor so as to blow superheated steam toward the web through a conveyor net, and a suction device is installed in the other conveyor. In addition, another injection device, which is a combination in which the arrangement of the nozzle and the suction device is reversed, is installed downstream of the injection device in the web traveling direction.
In addition, the hole diameter of the water vapor spray nozzle was 0.3 mm, and the nozzles were arranged in a line at a pitch of 1 mm along the conveyor width direction. The processing speed was 3 m / min, and the distance between the nozzle and the conveyor belt on the suction side was 7 mm.
The obtained nonwoven fabric structure had a board-like form, was very hard as compared with a general nonwoven fabric, and did not break even when the bending stress peak was exceeded, and there was no extreme decrease in stress. Further, the shape retention test did not change the shape and the mass did not decrease. The results are shown in Table 2.

[Examples 2 to 8]
Except that the polyester resin is a compound represented by the above chemical formula (I), 1,4-cyclohexanedicarboxylic acid, aliphatic dicarboxylic acid and isophthalic acid (IPA) copolymerization component and copolymerization amount as shown in Table 1 Obtained a wet heat adhesive fiber in the same manner as in Example 1. Further, this fiber was processed in the same manner as in Example 1 to obtain a nonwoven fabric structure. The obtained nonwoven fabric structure had a board-like form, was very hard as compared with a general nonwoven fabric, and did not break even when the bending stress peak was exceeded, and there was no extreme decrease in stress. Further, the shape retention test did not change the shape and the mass did not decrease. The results are shown in Table 2.

[Example 9]
Except that the wet heat-adhesive fiber used in Example 1 is 70% by mass, and a web of about 100 g / m ² with a basis weight of about 100 g / m ² mixed with 30% by mass of rayon fiber (1.4 dtex, 44 mm length) is used. A nonwoven fabric structure of the present invention was obtained in the same manner as Example 1. The results are shown in Table 2.
The obtained nonwoven fabric structure also had a board-like form, and showed the same bending behavior although slightly softer than the nonwoven fabric structure of Example 1.
Further, in the form retention test, a slight loss of fiber was observed, but the mass reduction was about 1%.

[Example 10]
Seven webs of about 100 g / m ² per unit web containing 50% by mass of the wet heat adhesive fiber used in Example 1 and 50% by mass of the rayon fiber used in Example 9 were stacked, and the conveyor on the nozzle and suction side A nonwoven fabric structure of the present invention was obtained in the same manner as in Example 1 except that the distance from the belt was 10 mm. The results are shown in Table 2.
The obtained nonwoven fabric structure had a board-like form, and showed the same bending behavior although it was softer than the nonwoven fabric structure of Example 9.
Further, in the form retention test, some fiber dropping was observed, but the mass reduction was about 4%.

[Example 11]
Seven webs with a weight of about 100 g / m ² mixed with 30% by mass of the wet heat adhesive fiber used in Example 1 and 70% by mass of the rayon fiber used in Example 9 were used to convey the nozzle and the conveyor on the suction side. A nonwoven fabric structure of the present invention was obtained in the same manner as in Example 1 except that the distance from the belt was 10 mm. The results are shown in Table 2.
The obtained nonwoven fabric structure was softer and easier to bend than the nonwoven fabric structure of Example 1, but the bending behavior was the same.
Further, in the form retention test, slight fiber loss and form change were observed, but the mass reduction was about 8%.

[Example 12]
A fiber having a fiber cross-sectional structure as shown in FIG. 1, h is used as a composite fiber. The copolymer polyester resin of Example 1 and other components are ethylene-vinyl alcohol copolymer (ethylene content 44 mol%, The composite staple fiber (3 dtex, 51 mm length, 21 crimps / inch, crimp ratio 13.5%) having a resin composite ratio of 50/50 was used. In addition, the nonwoven fabric structure of the present invention was obtained in the same manner as in Example 1 except that the distance between the nozzle and the conveyor belt on the suction side was 10 mm. This nonwoven fabric structure also showed substantially the same bending behavior as the nonwoven fabric structure of Example 1. The results are shown in Table 2.
Further, in the form retention test, there was no change in form and no decrease in mass was observed.

[Example 13]
The nonwoven fabric of the present invention is the same as in Example 1 except that nine webs having a basis weight of about 100 g / m ² obtained in Example 1 are overlapped and the distance between the nozzle and the conveyor belt on the suction side is 10 mm. A structure was obtained. The results are shown in Table 2.
The obtained nonwoven fabric structure was very hard board-like compared with those obtained in Examples 1 to 12, but there was no extreme stress reduction even in the bending amount exceeding the bending stress peak. .

[Example 14]
The non-woven fabric structure of the present invention is the same as in Example 1 except that 20 webs having a basis weight of about 100 g / m ² obtained in Example 1 are overlapped and the distance between the nozzle and the suction side belt conveyor is 12 mm. Got. The results are shown in Table 2.
The obtained nonwoven fabric structure showed the same bending behavior as that obtained in Example 13, and was a hard board.
Further, in the form retention test, there was no change in form and no decrease in mass was observed.

[Example 15]
The non-woven fabric structure of the present invention is the same as in Example 1 except that 40 webs having a basis weight of about 100 g / m ² obtained in Example 1 are overlapped and the distance between the nozzle and the suction side belt conveyor is 10 mm. Got. The results are shown in Table 2.
The obtained nonwoven fabric structure showed the same bending behavior as that obtained in Example 7, and was a hard board.
Further, in the form retention test, there was no change in form and no decrease in mass was observed.

[Example 16]
The nonwoven fabric structure of the present invention is the same as in Example 1 except that four webs having a basis weight of about 100 g / m ² obtained in Example 1 are stacked and the distance between the nozzle and the conveyor belt on the suction side is 3 mm. Got the body. The results are shown in Table 2.
The obtained non-woven fabric structure was soft and could be bent easily because of its low basis weight, but there was no sudden stress drop even after the peak of bending stress, and it was obtained in Example 1. The bending behavior was similar to that of Further, when a form retention test was performed, although a slight change in form was observed, no mass reduction was observed.

[Example 17]
When a card web with a basis weight of about 150 g / m ² was used, the gap between the pair of conveyors carrying the web was low and the distance between the upper nozzle and the web was too large, and the temperature of the steam reached the web. Therefore, the nonwoven fabric structure of the present invention was obtained in the same manner as in Example 1 except that the distance was 2 mm. The results are shown in Table 2.
The obtained non-woven fabric structure was soft and could be bent easily because of its low basis weight, but there was no sudden stress drop even after the peak of bending stress, and it was obtained in Example 1. The bending behavior was similar to that of
Further, in the form retention test, although some form change was observed, no mass reduction was observed.

[Example 18]
A non-woven fabric structure of the present invention was obtained in the same manner as in Example 1 except that a card web having a basis weight of about 50 g / m ² was used and the distance between a pair of conveyors carrying the web was set to 2 mm. The results are shown in Table 2.
The obtained non-woven fabric structure was soft and could be bent easily because of its low basis weight, but there was no sudden stress drop even after the peak of bending stress, and it was obtained in Example 1. The bending behavior was similar to that of
Furthermore, in the form retention test, there was no change in shape and no decrease in mass was observed.

[Comparative Example 1]
As the wet heat adhesive fiber, the core component is polyethylene terephthalate, the sheath component is an ethylene-vinyl alcohol copolymer (ethylene content 44 mol%, saponification degree 98.4 mol%, core-sheath ratio = 50/50). A certain core-sheath type composite staple fiber (3 dtex, 51 mm long, 21 crimps / inch, 13.5% crimp) was prepared.
Using the core-sheath type composite staple fiber, a web having a basis weight of about 100 g / m ² was prepared by a card method, and seven sheets of this web were stacked to obtain a card web having a total basis weight of about 700 g / m ² .
The card web was transferred to a belt conveyor equipped with a 50 mesh, 500 mm wide stainless steel endless wire mesh. In addition, the same metal mesh was equipped in the upper part of the metal mesh of this belt conveyor, each rotated in the same direction at the same speed, and the belt conveyor which can adjust the space | interval of these both metal meshes arbitrarily was used.
Next, the card web is introduced into a steam jetting device provided on the belt conveyor, and 0.4 MPa of superheated steam is jetted perpendicularly to the card web from the device to perform steam treatment, thereby obtaining the nonwoven fabric structure of the present invention. It was. In the steam injection device, a nozzle is installed in one conveyor so as to blow superheated steam toward the web through a conveyor net, and a suction device is installed in the other conveyor. In addition, another injection device, which is a combination in which the arrangement of the nozzle and the suction device is reversed, is installed downstream of the injection device in the web traveling direction.
In addition, the hole diameter of the water vapor spray nozzle was 0.3 mm, and the nozzles were arranged in a line at a pitch of 1 mm along the conveyor width direction. The processing speed was 3 m / min, and the distance between the nozzle and the conveyor belt on the suction side was 7 mm.
The obtained nonwoven fabric structure had a board-like form, was very hard as compared with a general nonwoven fabric, and did not break even when the bending stress peak was exceeded, and there was no extreme decrease in stress. Further, the shape retention test did not change the shape and the mass did not decrease. The results are shown in Table 3.

[Comparative Example 2]
Except for using a web of about 100 g / m ² with a basis weight of about 100 g / m ² in which 70% by mass of the wet heat adhesive fiber used in Comparative Example 1 and 30% by mass of rayon fiber (1.4 dtex, 44 mm length) were used, A nonwoven fabric structure of the present invention was obtained in the same manner as Example 1. The results are shown in Table 3.
The obtained nonwoven fabric structure also had a board-like form, and showed the same bending behavior although slightly softer than the nonwoven fabric structure of Example 1.
Further, in the form retention test, a slight loss of fiber was observed, but the mass reduction was about 1%.

[Comparative Example 3]
Seven webs are stacked using a web of about 100 g / m ² with a basis weight of 50% by mass of the wet heat adhesive fiber used in Comparative Example 1 and 50% by mass of the rayon fiber used in Comparative Example 2, and the conveyor on the nozzle and suction side. A nonwoven fabric structure of the present invention was obtained in the same manner as in Example 1 except that the distance from the belt was 10 mm. The results are shown in Table 3.
The nonwoven fabric structure obtained in Comparative Example 3 also has a board-like form, and showed a similar bending behavior although it was softer than the nonwoven fabric structure of Comparative Example 2.
Further, in the form retention test, some fiber dropping was observed, but the mass reduction was about 4%.

[Comparative Example 4]
Seven webs of about 100 g / m ² per unit web, mixed with 30% by mass of the wet heat adhesive fiber used in Comparative Example 1 and 70% by mass of the rayon fiber used in Comparative Example 2, were used to convey the nozzle and the conveyor on the suction side. A nonwoven fabric structure of the present invention was obtained in the same manner as in Example 1 except that the distance from the belt was 10 mm. The results are shown in Table 3.
The obtained nonwoven fabric structure was softer and easier to bend than the nonwoven fabric structure of Example 1, but the bending behavior was the same.
Further, in the form retention test, slight fiber loss and form change were observed, but the mass reduction was about 8%.

[Comparative Example 5]
As the wet heat adhesive fiber, the core component is polyethylene terephthalate, the sheath component is an ethylene-vinyl alcohol copolymer (ethylene content 44 mol%, saponification degree 98.4 mol%, core-sheath ratio = 50/50). A certain core-sheath type composite staple fiber (manufactured by Kuraray, “Sophista”, 5 dtex, 51 mm long, 21 crimps / inch, 13.5% crimp rate), and between the nozzle and the conveyor belt on the suction side A nonwoven fabric structure of the present invention was obtained in the same manner as in Example 1 except that the distance was 10 mm. This nonwoven fabric structure also showed substantially the same bending behavior as the nonwoven fabric structure of Example 1. The results are shown in Table 3.
Further, in the form retention test, there was no change in form and no decrease in mass was observed.

[Comparative Example 6]
The non-woven fabric structure of the present invention is the same as Comparative Example 1 except that 12 webs having a basis weight of about 100 g / m ² obtained in Comparative Example 1 are overlapped and the distance between the nozzle and the conveyor belt on the suction side is 10 mm. Got the body. The results are shown in Table 3.
The obtained nonwoven fabric structure was a very hard board, but there was no extreme reduction in stress even when the bending amount exceeded the bending stress peak.

[Comparative Example 7]
The non-woven fabric structure of the present invention is the same as Comparative Example 1 except that 20 webs having a basis weight of about 100 g / m ² obtained in Comparative Example 1 are overlapped and the distance between the nozzle and the suction side belt conveyor is 10 mm. Got. The results are shown in Table 3.
The obtained nonwoven fabric structure showed the same bending behavior as that obtained in Comparative Example 6, and was a hard board.
Further, in the form retention test, there was no change in form and no decrease in mass was observed.

[Comparative Example 8]
The nonwoven fabric structure of the present invention is the same as Comparative Example 1 except that 40 webs having a weight per unit area of about 100 g / m ² obtained in Comparative Example 1 are overlapped and the distance between the nozzle and the suction side belt conveyor is 10 mm. Got. The results are shown in Table 3.
The obtained nonwoven fabric structure showed the same bending behavior as that obtained in Comparative Example 7, and was a hard board.
Further, in the form retention test, there was no change in form and no decrease in mass was observed.

[Comparative Example 9]
The nonwoven fabric structure of the present invention is the same as in Example 1 except that four webs having a basis weight of about 100 g / m ² obtained in Comparative Example 1 are stacked and the distance between the nozzle and the conveyor belt on the suction side is 3 mm. Got the body. The results are shown in Table 3.
The obtained nonwoven fabric structure was soft and could be bent easily because of its low basis weight, but there was no sudden stress drop even after the peak of bending stress, and it was obtained in Comparative Example 1. The bending behavior was similar to that of Further, when a form retention test was performed, although a slight change in form was observed, no mass reduction was observed.

[Comparative Example 10]
When using a card web having a weight per unit area of about 150 g / m ² using the fibers used in Comparative Example 1, the distance between the pair of conveyors having a low basis weight and carrying the web is too wide, and the distance between the upper nozzle and the web is too large. Since it becomes empty and the temperature of the steam decreases before reaching the web, the nonwoven fabric structure of the present invention was obtained in the same manner as in Example 1 except that this interval was set to 2 mm. The results are shown in Table 3.
The obtained non-woven fabric structure had a low basis weight and was flexible and could be bent easily. However, even when the peak of the bending stress was passed, there was no sudden stress reduction, and it was obtained in Example 17. The bending behavior was similar to that of
Further, in the form retention test, although some form change was observed, no mass reduction was observed.

[Comparative Example 11]
A hard nonwoven fabric of the present invention was obtained in the same manner as in Comparative Example 1 except that a card web having a basis weight of about 50 g / m ² was used and the distance between a pair of conveyors for carrying the web was set to 2 mm. The results are shown in Table 3.
The obtained nonwoven fabric structure was soft and could be bent easily because of its low basis weight, but there was no sudden stress drop even after the peak of bending stress, and it was obtained in Comparative Example 1. The bending behavior was similar to that of
Furthermore, in the form retention test, there was no change in shape and no decrease in mass was observed.

The non-woven fabric structure of the present invention thus produced has an extremely high bending strength, a deodorizing function, and a breathability while having a low density comparable to that of a general non-woven fabric. Using such performance, for example, various board materials such as wood and control panel have been used in the past, or performance such as breathability, heat insulation and sound absorption for these board materials. Can be applied to applications that are required simultaneously.
Specifically, for example, a building material board, a heat insulating material or a heat insulating board, a breathable board, a sound absorbing and insulating body (a sound insulating wall material, a sound insulating material for a vehicle, etc.), various interior materials (a sound absorbing material, a sound absorbing panel, a partition, Partitions, paper sliding doors, wallpaper, blinds, non-woven curtains, various carpets, artificial flower materials, non-woven tablecloths, cushions, cushions, bed mats), liquid absorbents (magic pens, fluorescent pens and other cores, ink retainers for inkjet printer cartridges, Fragrance transpiration core materials, humidifier filters, etc.), work materials, cushion materials, lightweight containers and partition materials, wiping materials (whiteboard erasers, dishwashing sponges, pen-type wipers), household goods ( Blanket, duvet cover, pillowcase, bed cover, bedding, toilet seat cover), and car floor car Pets ,, various pet tool ,, various sheets (for hospitals, other nursing), sanitary materials, various filters (liquid, air, etc.) can be applied to other various applications.

The schematic diagram which shows the cross-sectional shape of the composite fiber used for the nonwoven fabric structure of this invention.

Claims (6)

75 mol% or more of the dicarboxylic acid component is terephthalic acid and / or an ester-forming derivative thereof, a compound ( i ) represented by the following formula (I) as a copolymerization component, and (ii) a cyclohexazadicarboxylic acid and / Or its ester-forming derivative, (iii) is a fiber in which a polyester (A) comprising a fatty acid and its ester-forming derivative is partially exposed on the surface, and the copolymerization amount of compound (i) is 1. 0 mol% to 3.5 mol%, the copolymerization amount of (ii) is 2.0 mol% to 10.0 mol%, and the copolymerization amount of (iii) is 2.0 mol% to A non-woven fabric structure having a structure of 8.0 mol%, wherein the other component is composed of a composite fiber composed of the wet heat adhesive polymer (B), and the fibers are slightly fused.

[In the above formulas, R represents hydrogen or C 1 -C 10 alkyl group, or an ester-forming functional group carbon, X is also a quaternary phosphonium salt an alkali metal salt. ] A nonwoven fabric structure containing 20 to 100% by mass of the composite fiber and having a density of 0.05 to 0.5 g / cm ³ , wherein the bending stress in at least one direction is 0.05 MPa or more, 2. The nonwoven fabric structure according to claim 1, wherein a stress of 1/10 or more of a bending stress peak value is maintained even at a displacement twice as large as a displacement showing a bending stress peak in the correlation of displacement.   When the cross section of the nonwoven fabric is divided into three equal parts along the thickness direction, the fiber adhesion ratio in each of the three divided areas is 85% or less, and the difference between the maximum value and the minimum value of the fiber adhesion ratio is The nonwoven fabric structure according to claim 1 or 2, which is 20% or less.   4. The composite fiber according to claim 1, wherein the wet heat adhesive polymer (B) is an ethylene-vinyl alcohol copolymer having an ethylene unit content of 10 to 60 mol%. 5. Nonwoven structure.   In the composite fiber, 75 mol% or more of the dicarboxylic acid component is terephthalic acid and / or an ester-forming derivative thereof, and the compound (i) represented by the following formula (I) as the copolymerization component is further expressed as (ii) Cyclohexazadicarboxylic acid and / or ester-forming derivative thereof, (iii) polyester (A) comprising fatty acid and ester-forming derivative thereof and ethylene-vinyl alcohol copolymer having an ethylene unit content of 10 to 60 mol% It consists of a wet heat adhesive polymer (B) made of a coalescence, the mass ratio (A / B) of each component is 90/10 to 10/90, and the ethylene-vinyl alcohol copolymer is the fiber surface The nonwoven fabric structure according to any one of claims 1 to 4, wherein a part of the nonwoven fabric is continuously occupied in the length direction.   The composite fiber is a core-sheath type composite fiber, and the core component is terephthalic acid and / or an ester-forming derivative thereof of 75 mol% or more of the dicarboxylic acid component, and is represented by the following formula (I) as a copolymerization component. The compound (i) is further a polyester (A) composed of cyclohexazadicarboxylic acid and / or an ester-forming derivative thereof as (ii), and a fatty acid and an ester-forming derivative thereof as (iii), wherein the sheath component is an ethylene unit The nonwoven fabric structure according to claim 5, which is an ethylene-vinyl alcohol copolymer (B) having a content of 10 to 60 mol%.

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