JPH07207561A - Laminated nonwoven fabric and its production - Google Patents

Abstract

PURPOSE:To obtain a laminated nonwoven fabric having high peeling strength, excellent flexibility, good filter performance and water-absorptivity and exhibiting excellent mechanical characteristics such as tensile strength and tensile elongation and to obtain a process for the production of the nonwoven fabric. CONSTITUTION:A splittable binary conjugate fiber is produced by the composite melt-spinning of (A) a fiber-forming polymer and (B) a fiber-forming polymer incompatible with the polymer A and having a melting point lower than that of the polymer A by 30-180 deg.C. A fiber fleece produced from the conjugate fiber is subjected to division splitting treatment to effect the splitting of the conjugate fiber to a splitting ratio of >=60%. The obtained split nonwoven fabric is composed of the split fiber A having a fineness of 0.05-0.8 de and the split fiber B having a fineness of 0.05-2 de. The split nonwoven fabric is laminated to a cotton nonwoven fabric containing mutually interlocked cotton fibers. A laminated nonwoven fabric having the split nonwoven fabric and the cotton nonwoven fabric laminated and integrated with each other can be produced by softening or melting the split fiber B and embedding the cotton fiber in the molten split fiber B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated non-woven fabric obtained by laminating a split non-woven fabric containing split fibers and a cotton non-woven fabric consisting of cotton fibers, and a method for producing the same. A laminated non-woven fabric which is highly flexible, has excellent filter performance and water absorbability, and can be used in a wide range of applications such as medical / sanitary materials, clothing, daily life related materials, industrial materials, etc. The present invention relates to a manufacturing method.

[0002]

2. Description of the Related Art Conventionally, various laminated non-woven fabrics are known in which a non-woven fabric made of thermoplastic fibers and a non-woven fabric made of natural fibers such as cotton fibers are laminated (Japanese Patent Publication No. 54-24506).
Issue). This laminated non-woven fabric is mainly intended to realize high tensile strength by a non-woven fabric made of thermoplastic fiber and to realize good water absorption by a non-woven fabric made of cotton fiber or the like. The layers of such a laminated nonwoven fabric are bonded together by various methods. For example, it is known to laminate by interposing an adhesive layer between both nonwoven fabrics. However, when an adhesive layer is used, this forms a film, which reduces the air permeability of the laminated nonwoven fabric, making it impossible to obtain good filter performance and also reducing the flexibility of the laminated nonwoven fabric. was there.

Further, after laminating both nonwoven fabrics, the nonwoven fabrics are treated at a high temperature to soften or melt the thermoplastic fibers, and at that time, cotton fibers or the like are pressure-welded to fuse the thermoplastic fibers and the cotton fibers or the like. It is also known. However, according to this method, when the thermoplastic fiber is softened or melted, it tends to be in a plate shape, and like the case where the adhesive layer is used, the breathability of the laminated nonwoven fabric is lowered and good filter performance can be obtained. In addition, there is a drawback that the flexibility of the laminated nonwoven fabric is reduced.
Therefore, it is conceivable to use a composite fiber in which a low melting point component and a high melting point component are compounded in a side-by-side type or a core-sheath type as the thermoplastic fiber. In this case,
It is considered that the low-melting point component softens or melts, but the high-melting point component does not soften or melt, so that it is unlikely to form a plate and the above-mentioned drawbacks are eliminated. However, in the case of the composite fiber, since the low-melting point component and the high-melting point component exist in close contact with each other, the cotton fiber or the like is not sufficiently embedded in the softened or melted low-melting point component, and the heat is There was a tendency that fusion with the plastic fiber was not sufficient. Therefore, there is a drawback that the bonding force between the layers of both nonwoven fabrics is weak and the layers are easily separated.

[0004]

Therefore, the present invention uses a thermoplastic fiber having a low melting point component and a composite fiber composed of a low melting point component and a high melting point component in a split state. By eliminating the close contact with the high melting point component and allowing the cotton fiber to be sufficiently embedded in the low melting point component, the delamination strength between the nonwoven fabric made of thermoplastic fiber and the nonwoven fabric made of cotton fiber can be increased and It is intended to prevent the flexibility and the air permeability of the obtained laminated non-woven fabric from being easily lowered.

[0005]

Means for Solving the Problems That is, the present invention provides a fiber-forming polymer A and a melting point which is incompatible with the polymer A and which is lower than the melting point of the polymer A by 30 to 180 ° C. A fineness of 0.05 formed by the polymer A, which is produced by splitting and splitting the splittable two-component composite fiber in which the fiber-forming polymer B having ~ 0.8 denier split fiber A and the polymer B has a fineness of 0.05 to 2
A laminated non-woven fabric obtained by laminating a split non-woven fabric containing denier split fibers B and a cotton non-woven fabric in which cotton fibers are entangled with each other, and at least a boundary surface between the split non-woven fabric and the cotton non-woven fabric. The laminated nonwoven fabric characterized in that the cotton fiber nonwoven fabric and the cotton nonwoven fabric are bonded together by a fixing area in which the cotton fiber located in the above is fixed in a state of being embedded in the melted fiber split fibers B. The present invention relates to a nonwoven fabric and a method for manufacturing the same.

First, the split nonwoven fabric used in the present invention will be described. This split nonwoven fabric splits split bicomponent composite fibers into split fibers with a split ratio of 60% or more.
It mainly contains the obtained split fiber.

The split type bicomponent conjugate fiber used here is a composite in which a fiber-forming polymer A and a fiber polymer B are independently splittable, for example. The cross section shown in FIGS. In addition, in FIGS. 1 to 4, the polymer A is shown by the hatched portion, and the polymer B is shown by the dotted portion. Polymer B is
It is incompatible with this polymer A. The incompatibility of the polymer A and the polymer B is to make the polymers A and B easy to be split and split by giving an impact or the like. The melting point of the polymer B is lower than that of the polymer A by 30 to 180 ° C. The melting point of the polymer B is
When the temperature is higher than this range, when the polymer A is softened or melted, the polymer B is also likely to be softened, and the polymers A and B are fused with each other to form a plate-like shape, which has air permeability and flexibility. It is not preferable because a laminated non-woven fabric excellent in heat resistance cannot be obtained.
On the contrary, when the melting point of the polymer B is lower than the above range, it becomes difficult to produce the splittable bicomponent conjugate fiber composed of the polymers A and B by the melt spinning method. In addition,
The melting points of the polymers A and B are measured by the following method. That is, using a DSC-2 type differential scanning calorimeter manufactured by Perkin Elmer Co., Ltd., the temperature that gives the maximum value of the melting endothermic peak obtained by heating from room temperature at a temperature rising rate of 20 ° C./min was taken as the melting point.

The split type bicomponent conjugate fiber formed of the polymers A and B is generally used in the form of continuous fiber, but it may be used in the form of staple fiber. The fineness of the splittable bicomponent conjugate fiber can be set arbitrarily, but is generally preferably in the range of 2 to 10 denier. When the fineness is less than 2 denier, it tends to be difficult to obtain the splittable bicomponent composite fiber by the melt spinning method. Conversely, if the fineness exceeds 10 denier,
The fineness of the split fibers A made of the polymer A or the split fibers B made of the polymer B generated after the split splitting tends to be too large, and the flexibility of the obtained laminated nonwoven fabric tends to decrease.

As a specific combination of the polymer A and the polymer B (polymer A / polymer B), typically, a polyamide-based polymer / polyolefin-based polymer, a polyester-based polymer / polyolefin-based polymer is used. Examples thereof include coalesce, polyamide-based polymer / polyester-based polymer and the like. Besides this, any combination may be adopted as desired. In particular, when a combination of polyester polymer / polyolefin polymer is adopted, both are excellent in hydrophobicity, so that one side is water-absorbing and the other side is hydrophobic. A laminated non-woven fabric having the above will be obtained.

Examples of the above-mentioned polyolefin polymer include ethylene, propylene, butene-1, penten-1,
3-methylbutene-1, hexene-1, octene-1, dodecene
-1, Octadecene-1 etc. aliphatic α with 2 to 16 carbon atoms
Examples include homopolyolefins obtained by homopolymerization of monoolefins and copolymerized polyolefins obtained by mixing and polymerization. Aliphatic α-monoolefins are also other olefins and / or small amounts (up to about 10% by weight of the polymer) of other ethylenically unsaturated monomers such as butadiene, isoprene, pentadiene-1,3, styrene, α. -It may be copolymerized with an ethylenically unsaturated monomer such as methylstyrene. Especially when polyethylene is used as the polyolefin resin, propylene, butane-1, hexene-1, octene up to about 10% by weight of the polymer is used.
Those obtained by copolymerizing a higher α-olefin such as -1 are preferred.

Examples of the above-mentioned polyamide polymer include nylon-4, nylon-46, nylon-6, nylon-
66, nylon-610, nylon 11, nylon-12, polymeta-xylene adipamide (MXD-6), polyparaxylene decanamide (PXD-12), polybiscyclohexylmethane decanamide (PCM-12), etc. are used. To be done. Further, it is also possible to use a copolyamide in which a plurality of monomers constituting such a polyamide polymer are used.

Examples of the above-mentioned polyester polymer include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, naphthalene-2,6-dicarboxylic acid, or fatty acids such as adipic acid and sebacic acid as acid components. Group dicarboxylic acids and their esters are used as the alcohol component, ethylene glycol, diethylene glycol,
A homopolyester or a copolyester obtained by condensing both diol compounds such as 1,4-butanediol, neopentyl glycol, cyclohexane-1,4-dimethanol and the like is used. Further, in this polyester and the like, paraoxybenzoic acid, 5-sodium sulfoisophthalic acid, polyalkylene glycol,
Pentaerythritol, bisphenol A, etc. may be added or copolymerized.

As the other polymer for forming the polymer A or B, for example, a vinyl polymer can be used. Specifically, polyvinyl alcohol, polyvinyl acetate, polyacrylic acid ester, ethylene-vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride and the like are used. Moreover, what copolymerized various monomers which comprise these is also used. As the polymer other than the vinyl polymer, a polyphenylene polymer or a copolymer thereof can be used.

The polymers A and B may be selected from matting agents, pigments, flameproofing agents, deodorants, antistatic agents, antioxidants, ultraviolet absorbers and the like, as long as the objects of the present invention are not impaired. Additives may be added.

The splittable bicomponent conjugate fiber in the present invention can be generally produced by the following method. That is, the polymers A and B are spun by a conventionally known melt composite spinning method, and are cooled by a blowing air using a conventionally known cooling device such as lateral spraying or annular spraying, and then generally air is used. Use soccer to pull and thin to the target fineness. At this time, the towing speed is 3000 m / min or more,
It is particularly preferably 4000 m / min or more. This is because high-strength splittable bicomponent conjugate fibers can be obtained, the tensile strength of the resulting split nonwoven fabric is improved, and the dimensional stability is improved.

To obtain a split nonwoven fabric using the split type bicomponent composite fiber thus obtained, for example, the following method is used. That is, the split type bicomponent composite fiber that was pulled by using an air sucker and then discharged from the air sucker is generally passed through a corona discharge area in a high piezoelectric field or a friction collision zone, Charge the fiber. Then, the fibrous aggregate is obtained by accumulating it on a moving and accumulating device such as a conveyor composed of a screen. The basis weight of this fiber assembly is preferably about 150 g / m ² or less. Weight is
If it exceeds 150 g / m ^{2, it} will be
Substantially all of the thickness of the fiber assembly will tend to prevent the splittable bicomponent composite fibers from being split and split. That is, undivided split-type two-component composite fibers tend to remain in the central portion of the thickness of the split nonwoven fabric. However, even in such a case, since the split fiber split is present on at least one surface of the split nonwoven fabric, it is still one embodiment of the present invention.

As a method for splitting and splitting the splittable bicomponent composite fiber in the fiber assembly, the following method can be used. For example, (a) a method in which a fiber punch is needle-punched, and a split-type bicomponent composite fiber is impacted with a needle to split and split the fiber, and (b) a chemical is added to the fiber aggregate to give a polymer. A method of dissolving a part of the surface of A or B and splitting split bicomponent composite fibers into split fibers.
(c) A method of subjecting a fiber assembly to a high-pressure liquid flow to split and split the split-type bicomponent composite fiber by this impact, (d)
A method of putting the fibrous aggregate in a flowing liquid to give a kneading action or a mechanical kneading action and splitting the splittable bicomponent composite fiber into split fibers by its buckling force is known. Can be mentioned. In the present invention, this split splitting method may be any method, but (c)
Alternatively, it is preferable to employ the method (d). This is because according to these methods, it is possible to obtain a split nonwoven fabric having a low basis weight and a high quality. Further, these methods are further less prone to pollution, and are simple, so that they are economical.

By the above-described split fiber splitting method, the polymer A and the polymer B existing in the split type two-component composite fiber are separated to obtain split fiber A composed of the polymer A. The fibers are split and split into split fibers B composed of the polymer B. Split fibers rarely occur at all the positions of the split type two-component composite fiber, and it is common that split parts and unsplit parts are mixed. In the present invention, it is necessary that the splitting ratio indicating the percentage of splitting portions is 60% or more, preferably 80% or more, more preferably 90%.
As described above, it is most preferably 95 to 98%. When the splitting ratio is less than 60%, split fiber B composed of polymer B
The ratio of B decreases and the number of places where the polymer B and the polymer A are in a state of being in contact with each other without being separated yet increases. Therefore, treating the split nonwoven fabric in such a state at high temperature,
Even if the polymer B is softened or melted to embed the cotton fibers in the cotton nonwoven fabric, since it is in close contact with the polymer A, it cannot be embedded sufficiently and a laminated nonwoven fabric having high delamination strength cannot be obtained. , Not preferable. Here, the splitting ratio is calculated by the following formula from 10 selected arbitrary areas of the split nonwoven fabric, taking a cross-sectional photograph by enlarging the cross section 100 times, and then taking 10 cross-sectional photographs. It means the average value of things. Note Split ratio (%) = (N / M) × 100 (where N represents the total number of split fibers A and B that have been completely split, and M represents split fibers and unsplit fibers. Indicates the total number of things.)

In the present invention, the fineness of the split fiber A after the split splitting is 0.05 to 0.8 denier, preferably 0.08 to 0.5 denier, and more preferably 0.1 to 0.3 denier. If the fineness of the split fiber A exceeds 0.8 denier, the diameter of the split fiber A is too large, the rigidity is increased, and the flexibility of the resulting laminated nonwoven fabric is reduced, which is not preferable. On the contrary, it is difficult to manufacture the split fiber A with a fiber of less than 0.05 denier. That is, it is practically difficult to spin such a fine denier fiber by the melt composite spinning method, and it becomes difficult to obtain the splittable bicomponent composite fiber inexpensively or rationally.

On the other hand, the fineness of the split fibers B after the split splitting may be slightly larger than that of the split fibers A. Because the split fiber B has a role of softening or melting in a later step to embed the cotton fiber, its rigidity directly affects the laminated non-woven fabric, and the flexibility is extremely increased. This is because it does not lower it. However, the fineness of the split fiber B also needs to be 0.05 to 2 denier, preferably 0.08 to 1.5 denier, and more preferably 0.1 to 1 denier. When the fineness of the split fibers B exceeds 2 denier, when the whole split fibers B are not heat-treated, there are split fibers B which are softened or melted and the cotton fibers are not embedded. ,by this,
It is not preferable because the flexibility of the obtained laminated nonwoven fabric is lowered. Conversely, setting the fineness of the split fiber B to less than 0.05 denier is difficult in manufacturing, as in the case of the split fiber A.

In the present invention, a cotton nonwoven fabric is laminated on such a split nonwoven fabric. The cotton non-woven fabric is one in which cotton fibers are entangled with each other to maintain a certain shape.
As the cotton fiber used here, combed cotton that has not been bleached, bleached cotton that has been bleached, or fluff obtained from a woven or knitted fabric is used. In order to obtain the fluff, a rag machine, such as a rag machine, a knot breaker, a garnet machine, and a turning machine, is used. To use the anti-hair-removing machine, multiple same anti-hair-removing machines are connected in series, although it depends on the fabric shape of the woven and knitted fabric to be fluffed and the thickness and twisting strength of the threads that make up the woven and knitted fabric. Or use a combination of two or more anti-fluffing machines. When using a fluffing machine, it is preferable that the opening rate is in the range of 30 to 95%. When the opening ratio is less than 30%, many unopened cotton fibers are present in the card web, so not only the surface of the resulting cotton non-woven fabric is rough, but, for example, the cotton fibers are separated from each other by high-pressure liquid flow. Even when three-dimensionally entangled, it is difficult for the high-pressure liquid flow to penetrate the unopened cotton fiber portion, and it tends to be difficult to obtain sufficient three-dimensional entanglement. On the other hand, if the opening ratio exceeds 95%, the length of the fluffed cotton fibers tends to become shorter,
Cotton fibers tend to fall off the surface of the resulting cotton nonwoven fabric, and it tends to be difficult to obtain sufficient surface friction strength. In addition, the opening rate here is calculated by the following formula. Note Opening rate (%) = [(weight of woven fabric-weight of cotton fiber) / weight of woven fabric] x 100

The cotton non-woven fabric is one in which cotton fibers are entangled with each other. This entanglement can be easily obtained by subjecting the cotton fiber aggregate to a needle punching treatment, a high-pressure liquid flow treatment, or the like. In particular, when the high-pressure liquid flow treatment is performed, the cotton fibers are three-dimensionally entangled with each other, the tensile strength and the like of the cotton nonwoven fabric are improved, and the flexibility is improved, which is preferable. Especially when obtaining a laminated non-woven fabric for sanitary materials or life-related materials,
It is preferable to use such a three-dimensionally entangled cotton nonwoven fabric.

The following method can be exemplified as a specific method for producing a cotton nonwoven fabric. A card machine is used to open the cotton fibers to create a card web having a predetermined basis weight. This card web can be a parallel web in which cotton fibers are arranged in a card machine proceeding method, a crosslaid web in which parallel webs are crosslaid, a random web in which cotton fibers are randomly arranged, or a parallel web with a random web. Any card web, such as a semi-random web in which the webs are arranged in an intermediate degree, can be used. In particular, when it is desired to develop the laminated nonwoven fabric according to the present invention as a raw material for clothing, a card web (specifically, a crosslay web or It is preferred to use a random web).

The web is then needle punched or high pressure liquid stream treated. When high-pressure liquid flow treatment is performed, for example, a device in which a large number of injection holes having a hole diameter of 0.05 to 1.5 mm, particularly 0.1 to 0.4 mm are arranged in a row or a plurality of rows with a hole interval of 0.05 to 5 mm, and an injection pressure is 5 to 150 kg / cm ^{It is performed} by jetting a ² G high-pressure liquid and causing the liquid flow to collide with the card web placed on the porous support member. The kinetic energy of this liquid flow causes the three-dimensional entanglement between the cotton fibers. The injection holes are arranged in rows in a direction orthogonal to the traveling direction of the card web. As the high-pressure liquid, room temperature water or warm water can be used.
The distance between the injection holes and the web is preferably 1 to 15 cm. If this distance is less than 1 cm, the texture of the cotton nonwoven fabric obtained by this treatment tends to be disturbed. On the other hand, if this distance exceeds 15 cm, the kinetic energy when the liquid flow collides with the web decreases, and the three-dimensional entanglement tends to be insufficient.

The treatment with the high-pressure liquid stream may be performed in at least two stages. That is, as the first-stage treatment, a high-pressure liquid flow having an injection pressure of 5 to 40 kg / cm ² G is injected to collide with the web, and the cotton fibers in the web are pre-entangled. In this first-stage treatment, if the pressure of the liquid flow is less than 5 kg / cm ² G, the cotton fibers in the web tend not to be preentangled. On the other hand, when the pressure of the liquid flow exceeds 40 kg / cm ² G, the kinetic energy of the liquid flow becomes too large, and the cotton fibers in the web are liable to be disturbed, resulting in disordered texture and mottled spots on the cotton nonwoven fabric. It tends to be easier. In the subsequent second stage treatment, a high-pressure liquid stream having a jet pressure of 50 to 150 kg / cm ² G is jetted to impinge on the pre-entangled web. Then, the cotton fibers in this web are further entangled three-dimensionally to form a cotton nonwoven fabric that is dense and has sufficient tensile strength as a whole. In this second stage treatment, if the pressure of the liquid stream is less than 50 kg / cm ² G, the kinetic energy is too small and the cotton fibers in the pre-entangled web will be further entangled three-dimensionally. Is not enough. On the other hand, when the pressure of the liquid flow exceeds 150 kg / cm 2 G, the resulting cotton nonwoven fabric tends to be too dense, and the bulkiness and flexibility tend to decrease. Depending on the weight of the web, as the third stage process following the second stage process, on the side opposite to the second stage process side (reverse web surface), the same condition as the second stage process is applied. Then, by performing the treatment again, it is possible to obtain a cotton non-woven fabric in which cotton fibers are densely entangled with each other on both sides.

As the porous supporting member for supporting the web used when performing the high pressure liquid flow treatment, for example, a perforated plate or a mesh screen made of wire mesh or synthetic resin is used. In addition, any other high pressure liquid stream that penetrates the web may be used. When using a mesh screen, it is preferable to use one having a pore size of 20 to 200 mesh. If the pore size is less than 20 mesh, the pores are too large and the cotton fibers in the web may pass through the mesh screen and fall off together with the high pressure liquid flow. Conversely, if the pore size exceeds 200 mesh, the pore size is too small, and the used high-pressure liquid stream tends to stay on the surface of the mesh screen.

The cotton nonwoven fabric obtained by the high-pressure liquid flow treatment contains excess water. Therefore, it is necessary to remove or evaporate this water. For example, a web containing excess water is squeezed using a squeezing device such as a mangle roll to mechanically remove the excess water to some extent. And
The remaining moisture is evaporated using a drying device such as a suction band type hot air circulation dryer to obtain a cotton nonwoven fabric that can be used in the present invention.

Although the cotton non-woven fabric can be obtained by the above-described method, the present invention is not limited to this method, and the non-woven fabric may be obtained by other methods.
The weight of the cotton non-woven fabric is preferably 30 to 200 g / m ² ,
In particular, it is more preferably 50 to 150 g / m ² . When the basis weight of the cotton nonwoven fabric is less than 30 g / m ² , the amount of cotton fibers per unit area is too small, so that a laminated nonwoven fabric excellent in water absorbency tends to be not obtained. Conversely, 200 g / m ²
When it exceeds, the cotton non-woven fabric becomes thick and the flexibility tends to decrease.

The split nonwoven fabric and the cotton nonwoven fabric described above are laminated and heat-treated to soften or melt the split fibers B in the split nonwoven fabric, and the softened or melted portion (that is, the melting portion) is cotton. By embedding cotton fibers in the non-woven fabric,
The split fiber non-woven fabric and the cotton non-woven fabric are bonded together at the boundary between the split fiber non-woven fabric and the cotton non-woven fabric, and the split fiber non-woven fabric and the cotton non-woven fabric are bonded together. Bonding and fixing the split fiber B and the cotton fiber may be performed in the entire area of the boundary surface between the split nonwoven fabric and the cotton nonwoven fabric, or may be performed only in a part of the area. In particular, when bonded and fixed only in a part of the area, the flexibility of the obtained laminated nonwoven fabric is not easily lowered, which is preferable. When binding and fixing in some areas, the area of the area is preferably 4 to 50%, particularly 8 to 25%, with respect to the entire area of the boundary surface between the split nonwoven fabric and the cotton nonwoven fabric. Is more preferable.
If the area of bonding and fixing is less than 4%, the peel strength between layers of the split nonwoven fabric and the cotton nonwoven fabric tends to decrease. On the other hand, if the area for bonding and fixing exceeds 50%, the flexibility and bulkiness of the laminated nonwoven fabric tend to be reduced.

When the parts are joined and fixed only in a part of the area, it is preferable that the areas are arranged so as not to be unevenly distributed. If they are unevenly distributed, the properties of the obtained laminated nonwoven fabric tend not to be uniform. In the dispersed arrangement, the shape of each point is generally circular, but may be arbitrary. Further, it may be arranged in a band shape with a constant interval.

In the present invention, as the method for laminating and bonding the split nonwoven fabric and the cotton nonwoven fabric, for example, the following method is preferably adopted. That is, it is preferable that a laminate obtained by laminating a split fiber nonwoven fabric and a cotton nonwoven fabric is introduced into an ultrasonic fusion machine and bonded. The ultrasonic fusion machine is a device that softens or melts the split fiber B by ultrasonic waves. Specifically, it is composed of an ultrasonic oscillator called a normal horn having a frequency of 19.15 KHZ, and a pattern roll having a convex protrusion such as a dot or a band on the circumference.
The convex protrusions arranged on the pattern roll may be arranged in one row or plural rows, and when the arrangement is plural rows, they may be arranged in parallel or in a staggered pattern. .

In the present invention, the laminate is passed between the ultrasonic oscillator and the pattern roll. Then, by the action of the ultrasonic waves oscillated from the ultrasonic oscillator, the split fiber B is softened or melted by frictional heat at the portion of the laminate that is in contact with the convex protrusion. At this time, air pressure is applied to the horn to apply pressure. The linear pressure between the horn and the pattern roll is usually about 1 to 10 kg / cm. By applying such a linear pressure, the cotton fibers are embedded in the softened or melted split fiber B, and are bonded and fixed. If the linear pressure is less than 1 kg / cm, the cotton fibers are not embedded in the softened or melted split fiber B, and the peel strength between the split nonwoven fabric and the cotton nonwoven fabric tends to decrease. On the other hand, if the linear pressure exceeds 10 kg / cm, the split fiber B may be thermally decomposed or holes may be formed in the laminated nonwoven fabric. As is clear from this description, when the shape of the tip of the convex protrusion is circular, the areas fixedly coupled are arranged in a scattered manner. Further, when the tip of the convex protrusion is in the shape of a strip, the areas that are coupled and fixed are arranged in a strip at regular intervals.

As described above, in the present invention, it is general to use an ultrasonic fusing device to form the area for bonding and fixing. The use of a hot embossing device instead of an ultrasonic fusing device makes it difficult to form the area of bond fixation. The heat embossing device is typically composed of a heated embossing roll having convex protrusions on the surface and a smooth roll having a smooth surface, but softened or melted split fibers like an ultrasonic fusing device. It is difficult to embed cotton fibers in fibers B. The reason for this is not clear, but it is considered that the split fiber B is softened or melted. Therefore, even when the heat embossing device is used, the cotton fibers can be satisfactorily embedded in the split fiber B by strictly setting the conditions such as the linear pressure and the heating temperature. It is difficult to adopt this method because it is difficult.

An example of the laminated non-woven fabric according to the present invention is shown in FIGS. 5 and 6. FIG. 5 schematically shows a cross section of the laminated non-woven fabric, in which a split non-woven fabric (hatched portion) and a cotton non-woven fabric (white background portion) are bonded, and a fixed area (necking Part X). FIG. 6 is a diagram schematically showing an enlarged view of the necking portion X. As is clear from FIG. 6, the cotton fibers are fixed in a state of being embedded in the melting portion of the split fiber B. Therefore, the peeling strength between the layers of the split nonwoven fabric and the cotton nonwoven fabric can be improved.

Next, the present invention will be described more specifically based on examples. The measuring method of each characteristic value and the like used in this example is carried out by the following method. [Melting point of polymer]: Temperature that gives the maximum value of the melting endothermic peak obtained by heating from room temperature at a temperature rising rate of 20 ° C./min using a DSC-2 type differential scanning calorimeter manufactured by Perkin Elmer. Was taken as the melting point. [Fineness of split fiber]: The cross-sectional area was calculated from the shape and dimensions in an electron micrograph, and the density was corrected. [Tensile strength of laminated non-woven fabric]: A value obtained by measuring the maximum tensile strength of a test piece having a width of 5 cm and a length of 10 cm according to the strip method described in JIS L-1096 and converting it into a basis weight of 100 g / m ² .
The tensile strength was measured in the longitudinal direction and the transverse direction. Here, the tensile strength in the machine direction means tensile strength in the machine direction, and the tensile strength in the transverse direction means tensile strength in a direction orthogonal to the machine direction. [Tensile elongation of laminated nonwoven fabric]: Elongation at the time of cutting when measuring tensile strength. The elongation was also measured in the longitudinal direction and the lateral direction. [Delamination strength of laminated nonwoven fabric]: A test piece having a width of 5 cm and a length of 10 cm was sampled from the laminated nonwoven fabric so that the longitudinal direction was the longitudinal direction. Using a constant-speed extension type tensile tester, one end of the split nonwoven fabric in this laminated non-woven fabric is clamped by one chuck, the other end of the cotton nonwoven fabric is clamped by the other chuck, and the tensile speed is 10 cm / min. The average value of the load values when peeled was defined as the delamination strength of the laminated nonwoven fabric. [Bending flexibility of laminated non-woven fabric]: A test piece having a width of 5 cm and a length of 10 cm was bent in the lengthwise direction to form a cylindrical body, and the joined end portions were joined as a bending resistance measurement sample. The axial direction (width direction of the test piece) of this sample was compressed at a compression rate of 5 cm / min using a constant-speed elongation type tensile tester, and the average of the maximum load values obtained was used to determine the bending resistance of the laminated nonwoven fabric. And [Air permeability of laminated nonwoven fabric]: Measured according to the Frazier method described in JIS L-1096. [Water Absorption of Laminated Nonwoven Fabric]: Measured according to the BYREC method described in JIS L-1096.

[0036]

【Example】

Example 1 As the fiber-forming polymer A, polyethylene terephthalate having [η] = 0.7 obtained by measurement at 20 ° C. in a mixed solvent having a melting point of 258 ° C. and phenol / chloroethane = 1/1 was prepared. On the other hand, as the fiber-forming polymer B, the melting point is 128 ° C.
Then, polyethylene having a melt index value (measured according to the method described in ASTM D1238 (E)) of 25 g / 10 minutes was prepared. Then, using a composite spinneret in which the resulting fiber cross section has a total division number of 24 in the form as shown in FIG. 1, the composite ratio of the polymer A and the polymer B is 1: 1 by weight, It was extruded at a single hole discharge rate of 1.2 g / min. In this way, the composite melt spinning was performed to obtain a split type two-component composite continuous fiber.

After the spun yarn is cooled, it is taken up with air sucker at a speed of 4500 m / min, opened by a corona discharge opener, collected and accumulated on the moving collecting surface, and a fiber aggregate is obtained. Got This fiber assembly was introduced into a hot embossing device to obtain a fiber fleece with a basis weight of 30 g / m ² . The embossing roll arranged in the hot embossing device has scattered projections at a ratio of 5% to the roll surface area, and the temperature is 6%.
It was set at 0 ° C. The fineness of the split type two-component composite continuous fiber collected from the fiber assembly is
It was about 2.5 denier.

Then, this fiber fleece is spun at a speed of 20 m /
Placed on a 100-mesh screen that moves for a minute, water is applied by a water applicator, and then the fiber fleece is subjected to high-pressure liquid flow treatment, and split splitting of split-type bicomponent composite continuous fibers. I went. This process is performed above the fiber fleece
The injection hole was located at 5 cm, and the front and back of the fiber fleece were subjected to high-pressure liquid flow treatment three times each under a water pressure of 50 kg / cm ² G. After this, squeeze excess water with mangle rolls,
Treated with a drying / heat treatment device kept in an atmosphere of 98 ° C,
A split nonwoven fabric was obtained. The split nonwoven fabric is split and split at a split rate of 91%, and the split fibers A (polyethylene terephthalate, that is, split fibers composed of the polymer A) are generated.
Has a fineness of 0.1 denier, and the split fiber B produced
(Polyethylene, that is, split fiber composed of polymer B)
The fineness was 0.1 denier.

On the other hand, a cotton nonwoven fabric having an average fineness of 1.5 denier and an average fiber length of 25 mm (cotton bleached cotton), in which the cotton fibers are three-dimensionally entangled, is prepared as follows. Manufactured. That is, with a random card machine,
Three-dimensional entanglement by creating a random card web in which cotton fibers are randomly arranged, feeding the obtained web to a 70-mesh screen moving at a speed of 20 m / min, and subjecting it to high-pressure liquid flow treatment. Processed. In the high pressure liquid flow treatment, the injection hole was located 5 cm above the web, and the high pressure liquid flow was applied in two stages. Water pressure is 30kg / cm ² G in the first stage treatment, and water pressure is 70kg / cm ^{2 in} the second stage treatment.
G. In the second stage treatment, the high pressure liquid stream was applied twice from the front and back of the web. Then, excess water was squeezed and removed with a mangle roll, and treated with a drying / heat treatment apparatus kept in an atmosphere of 98 ° C. to obtain a cotton nonwoven fabric.

Next, a laminate obtained by laminating a split fiber nonwoven fabric and a cotton nonwoven fabric is formed into an ultrasonic oscillator (horn) having a frequency of 19.15 KHZ and a pattern roll provided with scattered convex projections on the circumference. Introduced into the ultrasonic fusion machine consisting of and, at the boundary cotton between the split nonwoven fabric and the cotton nonwoven fabric, the cotton fibers are embedded and fixed in the split fiber B to obtain a laminated nonwoven fabric having a basis weight of 60 g / m ^2. Obtained. Here, in the pattern roll used, the convex protrusions were provided at a ratio of 10% to the roll surface area. The linear pressure between the convex protrusion and the horn is 2.
It was 5 kg / cm and the speed of the laminate moving in the ultrasonic fusing machine was 20 m / min. In addition, the area where the cotton fibers were embedded and fixed was only the area in contact with the convex protrusion in the laminated nonwoven fabric.

The properties of the laminated non-woven fabric obtained as described above are as shown in Table 1.

[Table 1]

Example 2 Nylon 6 having a relative viscosity of 2.65 measured at 25 ° C. in concentrated sulfuric acid having a melting point of 225 ° C. and 96% in place of the polyethylene (fiber-forming polymer B) used in Example 1 A splittable conjugate continuous fiber was obtained in the same manner as in Example 1 except that was used.

Then, the take-up speed of the air soccer
A fiber assembly was obtained in the same manner as in Example 1 except that the rate was 4600 m / min. Then, a fiber fleece was obtained in the same manner as in Example 1 except that the temperature of the embossing roll was changed to 150 ° C. The fineness of the split type bicomponent composite continuous fiber collected from the fiber assembly was about 2.3 denier.

A split nonwoven fabric was obtained in the same manner as in Example 1 except that the water pressure of the high-pressure liquid stream was 60 kg / cm ² G. The split nonwoven fabric is split and split at a split rate of 95%, and the split fibers A (polyethylene terephthalate, that is, split fibers composed of the polymer A) thus produced have a fineness of 0.1 denier. The fineness of the produced split fibers B (nylon 6, that is, split fibers composed of the polymer B) was also 0.1 denier.

Then, using the cotton nonwoven fabric used in Example 1, a laminated nonwoven fabric having a basis weight of 60 g / m ² was obtained in the same manner as in Example 1. The properties of the laminated nonwoven fabric obtained as described above were as shown in Table 1.

Example 3 The same fiber-forming polymers A and B as those used in Example 2 were prepared. Then, using a composite spinneret in which the resulting fiber cross section has a form as shown in FIG. 3 and the total number of divisions of polyethylene terephthalate is 8, polymer A
The polymer was extruded at a single hole discharge rate of 1.8 g / min so that the composite ratio of the polymer B and the polymer B was 1: 1 by weight. In this way, the composite melt spinning was performed to obtain a split type two-component composite continuous fiber.

Then, the take-up speed of the air soccer
A fiber aggregate was obtained in the same manner as in Example 2 except that the rate was 4700 m / min, and then a fiber fleece was obtained. The fineness of the split type two-component composite continuous fiber collected from the fiber assembly was about 3.4 denier. After that, a split nonwoven fabric was obtained in the same manner as in Example 2. This split nonwoven fabric has a split ratio
It is split and split at 95%, and the fineness of the produced split fiber A (polyethylene terephthalate, that is, split fiber composed of polymer A) is 0.2 denier, while the split fiber B (nylon 6 That is, the fineness of the split fiber composed of the polymer B) was 1.7 denier.

Then, using the cotton nonwoven fabric used in Example 1, a laminated nonwoven fabric having a basis weight of 60 g / m ² was obtained in the same manner as in Example 1. The properties of the laminated nonwoven fabric obtained as described above were as shown in Table 1.

Example 4 The same as Example 3 except that the pattern roll constituting the ultrasonic fusing machine is one in which the convex protrusions are provided at a ratio of 30% to the roll surface area. The basis weight 60
A laminated nonwoven fabric of g / m ² was obtained. The properties of the laminated nonwoven fabric obtained as described above were as shown in Table 1.

Comparative Example 1 Polyethylene terephthalate and polyethylene used in Example 1 were used and spun under the following conditions using a core-sheath type composite spinneret, with polyethylene terephthalate as the core and polyethylene as the sheath. A core-sheath type two-component composite continuous fiber arranged in the above was obtained. That is, the composite ratio of polyethylene terephthalate and polyethylene was 1: 1 by weight, and the single hole discharge rate was 1.2 g / min.

The take-up speed by air soccer is 4800
A fiber aggregate was obtained in the same manner as in Example 1 except that m / min was obtained, and then a fiber fleece was obtained. The fineness of the core-sheath type two-component composite continuous fiber collected from the fiber assembly is about
It was 2.3 denier. Then, the cotton nonwoven fabric used in Example 1 was used, and after this cotton nonwoven fabric and the fiber fleece were laminated, a laminated nonwoven fabric having a basis weight of 60 g / m ² was obtained in the same manner as in Example 1. The properties of the laminated nonwoven fabric obtained as described above were as shown in Table 1.

Comparative Example 2 The same polyethylene terephthalate as in Example 1 was used and a single-phase spinneret was used to extrude at a single hole discharge rate of 1.2 g / min. In this way, a monocomponent continuous fiber was obtained.
This single component continuous fiber is 5000m /
It was taken out at a speed of minutes, and thereafter, a fiber assembly and then a fiber fleece were obtained in the same manner as in Example 2. The fineness of the single-component continuous fiber collected from the fiber assembly was about 2.2 denier. Then, using the cotton nonwoven fabric used in Example 1, after laminating the cotton nonwoven fabric and the fiber fleece,
A laminated nonwoven fabric having a basis weight of 60 g / m ² was obtained in the same manner as in Example 1. The characteristics of the laminated non-woven fabric obtained as described above,
It was as shown in Table 1.

Comparative Example 3 A fiber assembly was obtained in the same manner as in Example 1 except that the basis weight of the fiber assembly was 60 g / m ² . This fiber assembly was introduced into a hot embossing device to obtain a fiber fleece with a basis weight of 60 g / m ² . The embossing roll arranged in the hot embossing device had scattered projections at a ratio of 10% to the roll surface area, and the temperature was set to 125 ° C. Then, a split nonwoven fabric was obtained under the same conditions as in Example 1.
The properties of this split nonwoven fabric were as shown in Table 1.

Comparative Example 4 A cotton nonwoven fabric was obtained under the same conditions as in Example 1 except that the basis weight was 60 g / m ² . The characteristics of this cotton nonwoven fabric were as shown in Table 1.

As is clear from Table 1, Examples 1, 2, and
The laminated non-woven fabric obtained by the methods according to 3 and 4 is one in which the split non-woven fabric composed of the split fibers A and B and the cotton non-woven fabric are firmly laminated and integrated, and have high peel strength. there were. Further, it was excellent in mechanical properties such as tensile strength and tensile elongation, was excellent in flexibility, and had good filter performance and water absorption.

On the other hand, the laminated non-woven fabric obtained by the method according to Comparative Example 1 was a core-sheath type two-component composite continuous material in which polyethylene terephthalate was used as the core and polyethylene was used as the sheath without using the split nonwoven fabric. Since the fiber fleece made of fibers was used, the fiber fleece and the cotton nonwoven fabric were not firmly integrated, and the peel strength was poor.
Further, since split fiber is not used, the flexibility and the filter performance are inferior. However, it was excellent in mechanical properties and water absorption. Since the laminated nonwoven fabric obtained by the method according to Comparative Example 2 also uses the fiber fleece formed of the one-component continuous fiber without using the split nonwoven fabric, like the case of Comparative Example 1, The peel strength was poor, and the flexibility and filter performance were poor.
And, it was excellent in mechanical properties and water absorption.

The non-woven fabric obtained by the method according to Comparative Example 3 was
It is composed only of split fiber non-woven fabric in which cotton non-woven fabric is not laminated. Therefore, although it was excellent in mechanical properties, flexibility and filter performance, it was inferior in water absorption. The non-woven fabric obtained by the method according to Comparative Example 4 is made of only the cotton non-woven fabric on which the split fiber non-woven fabric is not laminated. Therefore, although the water absorption performance was excellent, the mechanical properties and filter performance were poor.

[0058]

In the laminated nonwoven fabric according to the present invention, a split nonwoven fabric and a cotton nonwoven fabric are laminated, and the split nonwoven fabric is composed of split fiber A having a high melting point and split fiber B having a low melting point. Then, at the boundary surface between the two nonwoven fabrics, the cotton fibers in the cotton nonwoven fabric are embedded in the melted split fiber B. Therefore,
The split fiber nonwoven fabric and the cotton nonwoven fabric are firmly integrated. Moreover, since the split nonwoven fabric is formed of split fibers A and B having a small fineness, the split fiber has a low bending resistance. Therefore,
The split nonwoven fabric or the laminated nonwoven fabric in which it is laminated with a cotton nonwoven fabric is rich in flexibility and excellent in filter performance. Furthermore, only the split fiber B is melted,
Since the split fiber A is less likely to be softened or melted and melted, the air permeability is less likely to decrease, and good filter performance is less likely to be impaired. Further, the cotton non-woven fabric was rich in water absorption.

[0059]

EFFECT OF THE INVENTION The laminated non-woven fabric according to the present invention exhibits the above-mentioned actions synergistically and synthetically, has a high peeling strength, is rich in flexibility, has a good filter performance and a good water absorption property. It has good mechanical properties. That is, according to the present invention, it is possible to obtain a non-woven fabric having such characteristics. Therefore, the laminated non-woven fabric according to the present invention is preferably used for various applications such as medical / sanitary materials, clothing, life-related materials, and industry.

[Brief description of drawings]

FIG. 1 is a view showing an example of a cross section of a splittable bicomponent conjugate fiber used in the present invention.

FIG. 2 is a view showing an example of a cross section of a splittable bicomponent conjugate fiber used in the present invention.

FIG. 3 is a view showing an example of a cross section of a splittable bicomponent conjugate fiber used in the present invention.

FIG. 4 is a view showing an example of a cross section of a splittable bicomponent conjugate fiber used in the present invention.

FIG. 5 is a diagram schematically showing an example of a cross section of a laminated nonwoven fabric according to the present invention.

FIG. 6 is an enlarged view of a fixed area (necking portion X) where a split nonwoven fabric (hatched portion) and a cotton nonwoven fabric (white background portion) are attached in the cross section shown in FIG. It is the figure shown.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location D04H 1/54 QM D06M 17/00

Claims (3)

[Claims] 1. A fiber-forming polymer A, which is incompatible with the polymer A and has a melting point of 30 to 18 higher than the melting point of the polymer A.
A split-type two-component composite fiber in which a fiber-forming polymer B having a low melting point of 0 ° C. is formed by split splitting so as to have a splitting rate of 60% or more. The split fiber non-woven fabric containing the split fiber A having a fineness of 0.05 to 0.8 denier and the split fiber B having a fineness of 0.05 to 2 denier and the cotton fiber are entangled with each other. A laminated non-woven fabric obtained by laminating a cotton non-woven fabric, wherein the cotton fibers located at least at the boundary between the split non-woven fabric and the cotton non-woven fabric are fixed in a state of being embedded in the melted split fiber B. A laminated non-woven fabric, characterized in that the split non-woven fabric and the cotton non-woven fabric are pasted together according to a fixed area. 2. The laminated non-woven fabric according to claim 1, wherein the area of the fixed area is 4 to 50% of the total area of the boundary surface between the split nonwoven fabric and the cotton non-woven fabric. 3. A fiber-forming polymer A, which is incompatible with the polymer A and has a melting point of 30 to 18 higher than the melting point of the polymer A.
A split-type two-component composite fiber in which a fiber-forming polymer B having a low melting point of 0 ° C. is composited, and is produced by splitting the fiber so that the splitting ratio is 60% or more. Fineness 0.
A split fiber non-woven fabric containing split fiber A having a denier of 0.05 to 0.8 and split fiber B having a fineness of 0.05 to 2 denier composed of the polymer B, and a cotton non-woven fabric in which cotton fibers are entangled with each other. And then softening or melting at least a part of the split fiber B by introducing the laminate into an ultrasonic fusion machine, and at the same time, softening or melting the split fiber B into the cotton fiber. A method for producing a laminated non-woven fabric, which comprises partially embedding.