CN1685099A - Spun-bonded nonwoven fabric and sanitary supplies - Google Patents

Abstract

A spun-bonded nonwoven fabric constituted of a web of continuous filaments of thermoplastic synthetic fibers, the structure of which fabric is set by a pattern composed of areas which are produced by partially fusing the fibers by hot pressing and pierce through the fabric and concavely and convexly embossed patterns on the surfaces of the fabric which patterns are composed of high-density concave and convex areas of unbonded fibers respectively and the bulkiness of which fabric is 100 to 400 % in terms of the ratio of the thickness of the fabric inclusive of the convexly embossed pattern surface to the thickness of the low-density areas of the fabric. The application of a hydrophilic agent to the nonwoven fabric gives sanitary supplies such as disposable diaper.

Description

Spun-bonded non-woven fabrics and hygiene materials

technical field

The present invention relates to spunbonded nonwoven fabrics, in particular to nonwoven fabrics whose structure is fixed, soft, and Bulk spunbonded nonwovens, disposable hygiene materials and improved nonwovens for disposable hygiene materials.

Background technique

Hygienic materials used in diapers, sanitary napkins, etc. are generally composed of a surface layer that allows urine and excrement to pass through, an absorbent body, a waterproof back sheet, and a leak-proof flower called "three-dimensional gathers" that utilizes water resistance. Pattern (カフ) and so on. The materials used for these hygienic materials are mostly non-woven fabrics from the viewpoints of thinness, strength, softness when touching the skin, productivity, and price.

As a kind of hygienic material, the surface layer of disposable diapers is in direct contact with the skin, so it is required to have a soft touch, and at the same time, it is required to have strong instantaneous permeability of urine, less rewetting, and high The durability of repeated urine penetration and liquid permeability.

At present, non-woven fabrics are used, which are bulky fibers such as composite short fibers, which are welded by hot air or partial heat pressing. However, although this non-woven fabric connected by hot air has bulkiness and cushioning properties, in order to obtain sufficient cushioning properties, the weight per unit area of the non-woven fabric needs to be increased, and its surface is composed of composite fibers, which are passed through the hot air. The welding of the non-woven fabric fixes the structure of the non-woven fabric, so the non-woven fabric is relatively rough and hard to the touch.

In addition, the point-bonded nonwoven fabric in which the short fibers are thermally pressure-welded has low strength and is thin, so that the fiber ends of the short fibers may irritate the skin.

On the other hand, the non-woven fabric produced by the spunbond method is partially heat-pressed and welded to the filament web, and hydrophilized as needed, so it has high productivity, high strength, and soft touch. However, due to the shape and arrangement of fibers, compared with short-fiber non-woven fabrics, it is generally planar, and the properties such as liquid permeability and rewetting property are not sufficient. Known methods for improving the bulkiness of spunbond nonwoven fabrics include: connecting with a liquid-absorbent core, laminating a surface layer composed of an upper layer and a lower layer, and forming a perforated catheter with recesses through the upper layer. Method (JP-A-6-304203); Method for imparting and maintaining irregularities by thermally embossing a web composed of two-component fibers such as core-sheath composite fibers or side-by-side composite fibers (JP-A-11-286863) ; A method of thermally embossing a web composed of two-component fibers such as core-sheath composite fibers or side-by-side composite fibers to impart concavity and convexity, and to form the apex of the concave-convex shape into a film (JP-A-11-347062 ) wait. However, these methods are perforated or shaped and fixed, and the non-woven fabric lacks softness.

The invention described in Japanese Patent Publication No. 63-17944 related to the inventor's invention is a non-woven fabric composed of a filament net with a fineness of 0.5d to 5d, and has a partially bonded part and non-bonded uneven deformation . However, this invention is a technique of bending fibers at non-bonding parts, performing embossing, and kneading the fibers to make them bulky and softened, and does not relate to characteristics such as liquid permeability required for hygienic materials.

Regarding three-dimensional gathers on the other hand of sanitary materials, especially floral patterns for leakage prevention, back sheets, etc., laminated non-woven fabrics are used as non-woven fabrics with water resistance, in which filament nets and melt-blown fibers are laminated, Utilizes the strength of the former and the fine coverage and water resistance of the latter.

Compared with the existing monofilament net, this kind of laminated nonwoven fabric has better coverage, so it can realize its function under the condition of lower weight per unit area. Although with a long fiber web, the paper form of the meltblown web becomes stronger, and as the meltblown web is bonded, there is a harder feel like paper, especially as the weight per unit area It becomes low and tends to become a thin nonwoven fabric.

As a method for improving bulkiness, there is known a method of connecting a liquid-absorbent core, laminating a surface layer composed of an upper layer and a lower layer, and forming a recessed portion through the upper layer (Japanese Patent Laid-Open No. 6 -304203 bulletin); method of providing and maintaining unevenness by heat embossing nonwoven fabric composed of two-component fibers such as core-sheath composite fiber or side-by-side composite fiber (Japanese Patent Laid-Open No. 11-286863); A method of heat-embossing a nonwoven fabric composed of two-component fibers such as sheath-type composite fibers or side-by-side composite fibers to impart concavities and convexities, and to form the vertices of protruding portions with concavo-convex shapes into a film (JP-A-11-347062 ), etc. . However, these methods are perforated or shaped and fixed, and the non-woven fabric lacks softness.

The patent application publication (Japanese Patent Publication No. Sho 63-17944) related to the inventor's invention discloses a filament net with a fineness of 0.5d to 5d, which has partial bonding and non-bonding unevenness. of non-woven fabrics. However, the above-mentioned patent publications do not describe the content of using the melt-blown fiber web, and do not disclose the effect of improving the adhesion of the melt-blown fiber web shown in the present invention.

Contents of the invention

The object of the present invention is to provide an improved spunbond type that can solve the above problems and can be used as sanitary materials such as disposable diapers that are bulky, soft to the touch, have high water permeability, less rewetting, and excellent strength. non-woven fabric.

Another object of the present invention is to provide an improved hygienic material of a spunbonded nonwoven fabric by a spunbond method that can be produced with high productivity.

The basic composition of the non-woven fabric in the present invention is: a spunbonded non-woven fabric, which is a non-woven fabric mainly composed of a network of continuous filaments of thermoplastic synthetic fibers. The front and back of the non-woven fabric are fixed by a partially heat-pressed and welded fiber region pattern, and a concave pattern or a raised pattern composed of a high-density region of non-bonded fibers on both sides of the non-woven fabric structure. The bulk ratio represented by the ratio of the thickness of the nonwoven fabric occupied by the non-bonded fiber low density region to the thickness of the nonwoven fabric including the raised embossed surface of the nonwoven fabric structure is 100% or more.

One of the preferred basic aspects of the spunbonded nonwoven fabric of the present invention is a nonwoven fabric structure in which a meltblown fiber layer is added to a thermoplastic synthetic fiber filament layer.

That is, the basic properties such as bulkiness and softness required as a sanitary material can be further improved by the following spunbond nonwoven fabric: a spunbond nonwoven fabric formed of a composite network composed of at least one A layer of thermoplastic synthetic fiber continuous filament web and at least one layer of melt-blown fiber web are laminated. The structure of the non-woven fabric passes through the front and back of the non-woven fabric and integrates the partial hot-press fusion fiber region pattern, and the non-woven fabric. The two sides of the cloth structure are fixed by concave embossing or embossing patterns composed of high-density regions of non-bonded fibers, and the thickness of the non-woven fabric occupied by the low-density regions of non-bonded fibers is related to the The bulk ratio represented by the ratio of the thickness of the nonwoven fabric on the embossed surface of the nonwoven fabric is 100% or more.

The basic structure of the spunbonded nonwoven fabric (1) of the present invention is schematically shown in FIG. 1 . As shown in Figure 1(I) and Figure 1(III), the non-woven fabric structure is formed by (A) part of the heat-press fusion fiber region pattern (hereinafter sometimes only referred to as part of the heat-welded part) and (B) by the non-bonded fiber Debossed embossing or embossing made of high-density areas are fixed. The patterns (A) and (B) shown in Fig. 1 are schematic patterns, and the shapes and distances of (A) and (B) can be changed in actual patterns. Moreover, each pattern of (A) and (B) is independently arrange|positioned continuously or discontinuously on the front and back of a nonwoven fabric structure, respectively. In addition, the nonwoven fabric structure is connected to the above-mentioned (A) and/or (B), and contains (C) a low-density region of non-bonded fibers. Here (A) the pattern of partially thermocompression-fused fiber domains is applied by thermal embossing, and (B) the debossed or raised pattern consisting of high-density regions of non-bonded fibers is applied at a low temperature or temperature at which the fibers are not fused. The embossed pattern applied is a pattern embossed in opposite directions on the upper surface (first surface) and the lower surface (second surface) of the nonwoven fabric (see Fig. 1(III), Fig. 2-Fig. 4). A specific example of the spunbonded nonwoven fabric of the present invention is shown in FIG. 7 . In FIG. 7(I), the nonwoven fabric structure in which the embossed patterns of (A), (B) and (C) are formed can be seen. Fig. 8 (I) is the example of the spunbonded nonwoven fabric of the present invention that contains the lamination of melt-blown fiber web, and the example of Fig. 7 is the same, it can be seen that (A), (B) and (C) are formed Patterned non-woven structure. Specific aspects of the fixing structure of the nonwoven fabric structure of the present invention including the above (A), (B) and (C) can be clearly understood from the above-mentioned FIGS. 7 and 8 .

In the spunbonded nonwoven fabric of the present invention, the bulkiness depends on the thickness (a) of the nonwoven fabric occupied by the low-density region of non-bonded fibers in the nonwoven fabric structure (a) and the raised embossed pattern of the nonwoven fabric. The ratio of the thickness (b) of the non-woven fabric on the surface, that is, the value calculated by the following formula is expressed (see FIG. 1(III)).

    Expanding rate (%) = (b/a) × 100

Here, the thickness (a) of the low-density region of non-bonded fibers is the thickness before embossing at low temperature, so the bulk factor can also be calculated from the difference in thickness before and after embossing. Bulk is very important in determining the softness of nonwovens, which means embossing at low temperatures applies a kneading action to the nonwoven construction.

Furthermore, the spunbonded nonwoven fabric of the present invention mainly contains a hydrophilizing agent in the high-density region (B) of non-bonding fibers, so that the nonwoven fabric can be improved to satisfy both bulkiness and hygienic performance. Four characteristics of softness, water permeability and moisture return.

The present invention is discussed in detail below.

As the fibers constituting the spunbonded nonwoven fabric of the present invention, polyolefin fibers such as polypropylene, polyethylene, or copolymers thereof have low water retention properties and good moisture return properties, and polyethylene terephthalate Polyester fibers such as alcohol esters, polybutylene terephthalate, polytrimethylene terephthalate (PTT), or their copolymers are better in terms of waist strength and dryness. Nylon 6, 66, 610, 12 , or polyamide fibers such as copolymers thereof are preferable in that a nonwoven fabric having stable softness can be obtained. These composite fibers, mixed fibers, and fibers having other special functions may be mixed as needed.

Non-woven fabrics need to be strong enough to cope with the body movement phase when the surface is wet with urine, and from the viewpoint of productivity, it is preferable to form a web with continuous long fibers (filaments) and connect them And the formed non-woven fabric made by spunbond method. The non-woven fabric produced by the spunbond method has practical strength due to its long fiber length, and has good air permeability, and is different from wet or dry manufacturing, and does not require oil treatment, etc., and the fibers can be directly sheeted (シ一ト化), so properties such as the unique water repellency of fibers can be utilized.

In order to maintain the strength and softness of the nonwoven fabric and the feel of the fiber itself, the connection of the fiber webs in the nonwoven fabric structure is preferably performed by partial thermocompression welding. The thermocompression welding area ratio in partial thermocompression welding is preferably 5 to 40%, more preferably 5 to 25%, from the viewpoint of maintaining strength and flexibility. In addition to using an ultrasonic welding machine, partial thermocompression welding can also be carried out by passing through a mesh between hot embossing rolls heated to below the melting point of the constituent fibers, so that the front and back of the non-woven fabric structure are integrated. For example, floating and sinking patterns such as pin point shapes and rectangular shapes are scattered on the entire surface of the non-woven fabric. Of course, the thermocompression-welded part is a film-like part that is pressed and bonded, and the fibers around it have a unique feel to the fibers used.

The thickness of the nonwoven fabric produced by thermocompression welding only by this portion varies depending on the fiber constitution, embossed shape, and arrangement, but the thickness of the non-crimped fibers of ordinary circular cross-section fibers is not very large. In particular, in the usual webs produced by the spunbond method, the arrangement of the fibers at the time of formation is planar and not bulky.

In addition, the partial thermocompression welding refers to the formation of partial application of pressure in an embossed pattern at a temperature not higher than the melting point of the constituent fibers in the part that is partially connected by heat and pressure. Unlike the fibers that are fused and formed into a film at a temperature above the melting point, it is the part of the "film" that is connected while maintaining the shape of the fiber. In order to distinguish it from the high-density part formed by non-bonding concave-convex processing, it is called partial hot pressing. welding.

As described above, the spunbonded nonwoven fabric of the present invention is a nonwoven fabric in which the front and back are integrated by partial thermocompression welding, forming the following nonwoven fabric structure: having a thermocompression fusion part on one surface. The concave part of the high-density region of non-bonded fibers with different patterns has the convex part of the high-density region of non-bonded fibers in the opposite surface, so the non-woven fabric structure is integrated from the inside and the outside by the scattered partial heat-press welding parts, The other parts are composed of two regions with different fiber densities, the raised or depressed embossing pattern in the high-density region of unbonded fibers, and the low-density region of unbonded fibers, which are respectively affected by the kneading effect of the low-temperature embossing forming process. A structure in which the fibers themselves are easy to move is formed, thus forming a non-woven fabric structure with a soft touch and bulkiness.

The high-density region of non-bonded fibers refers to the region shown in B of Figures 1 to 3, where the fibers are not melted or connected, and is compressed by the concave-convex part of the embossing roller for concave-convex processing, and the fibers are compressed The densely dense fiber region is, for example, in the range of 15 to 35% in terms of fiber volume fraction. And in the present invention, the area ratio of the high-density region of non-bonded fibers is 5-50%, preferably 5-25%. Partial thermocompression welding is calculated based on the shape of the embossed pattern of thermocompression welding. Expand the non-woven fabric of the test material under a microscope, measure its size and spacing according to the outline of the welded and film-shaped part, obtain its area, and calculate the area ratio of the entire area of the test material.

The low-density region of non-bonded fibers refers to the region shown in C in Fig. 1, which corresponds to the part where the fibers are not welded or connected, and is not compressed by the embossing roller for concave-convex processing, and is the same as the high-density region of non-bonded fibers. A region that is not denser than fibers and has approximately the aggregate density of fibers before roughening. Therefore, the fibers in the low-density region have bulkiness and freedom of movement, and have the soft touch inherent to the fibers. For example, the fiber volume fraction of the low density regions of non-bonded fibers is in the range of 5-15%. The area of the high-density region of non-bonded fibers is in the high-density region of the fibers formed by extrusion embossing patterns, select the track where the constituent fibers are extruded, disconnected or partially deformed, obtain the area, and calculate the relative The area ratio of the overall area of the test material. The fiber shape of the high-density region of non-bonded fibers includes only fibers with shrinkage of constituent fibers or fibers with little deformation.

The high-density area of unbonded fibers is thinner and the fibers are dense, and the ones treated with a hydrophilizing agent are rich in hydrophilizing agents in the high-density area, so the liquid permeability is better, the outer surface is smooth, and there is Dry and soft to the touch.

The non-bonded low-density area is thicker than the high-density area, the aggregate density of the fibers is small, soft and bulky, the liquid permeability is good, and it also has a barrier effect on the liquid rewetting, and has good liquid return. Wet (wet back).

The above function will be described with reference to the cross-sectional views of FIGS. 1-3 . 1 to 3 illustrate the structural features of the nonwoven fabric of the present invention with easy-to-understand schematic diagrams.

(A) Partial thermocompression welding is a region that functions to maintain the overall strength of the nonwoven fabric, and has an appropriate area ratio.

(B) The non-bonded high-density region is the B region, and has a shape protruding from the surface of the nonwoven fabric, so it has the function of making the whole nonwoven fabric bulky. And since the hydrophilizing agent is rich in the B region, it has the effect of greatly increasing the hydrophilicity of this part and improving the permeability of the liquid passing through the B region.

(C) The non-bonding low-density region is the C region, and its role is to increase the degree of freedom of the fibers, improve flexibility, and impart a soft touch. In addition, the C region has a barrier effect on the return of liquid from the absorbent body through the bulking effect, and can improve the rewet property.

Also, it has an effect of being easy to bend at the boundary with B. Thus, as a characteristic of this invention, each area|region of (A), (B), and (C) has the above-mentioned function respectively, and has the function suitable for a hygienic material as a whole.

The non-woven fabric in the present invention is completely different from the relatively hard and rough non-woven fabric formed by using composite fibers shown in the prior art and being welded by connection and hot air treatment.

In the present invention, by imparting non-cohesion and concave-convex deformation to the fiber layer with a degree of freedom, a fiber layer with partial deformation (stretching) can be produced, so its cushioning performance is good, so it is difficult to be compressed when a load is applied. characteristics. Therefore, even under load conditions, it is bulky and porous, so the liquid is easy to penetrate (the speed of liquid penetration is fast), and once permeated, the absorbed liquid is difficult to rewet.

The concavo-convex deformation applied to the non-woven fabric in the present invention is a concave or convex deformation of any shape that is partially inconsistent with the pattern of the partially bonded joint, and the shape, size, and depth of the concave or convex part are related to the bonded pattern. , is important for the softness effect.

The shape of the concave portion or the convex portion is, for example, configured as a continuous connection or a discontinuous shape such as a straight line, a curve, an edge, a circle, a pear-skin shape, etc. From the perspective of the softness effect, the depth of the concave portion or the convex portion is about 0.2-5mm Works best at depths. In addition, the size of the discontinuous convex pressing surface is preferably 0.1-5 mm, or the pitch of the concave or convex is preferably 0.5-5 mm.

Fig. 1 is a schematic diagram of the overall plan view configuration of the nonwoven fabric of the present invention. Fig. 2 and Fig. 3 are diagrams illustrating examples of angular embossing applied to a nonwoven fabric. Fig. 2 and Fig. 3 are two examples of patterns not combined with concavo-convex processing, and in the figures, the patterns and their distribution of the thermocompression welding part are omitted.

For example, as shown in FIG. 3, a discontinuous distribution of depressions is formed in a high density area by pressing an embossing pattern interspersed with protrusions. Furthermore, as shown in FIG. 2 , the continuous embossing pattern of the extruded convex portion makes the non-extruded portion protrude from the fiber layer while the high-density region is continuous. The deformation pitch of the connecting pattern depends on the pattern, but is preferably 1-5 mm, and the size of the concave part is preferably a line or a dotted line with a width of 0.02-3 mm.

The bulkiness of the non-woven fabric structure is improved by providing a high-density area to increase the thickness by the bulk effect, and the thickness of the non-woven fabric varies little with the load. The present inventors found that the concentration of the hydrophilizing agent becomes larger in the high-density region of non-bonded fibers after applying the hydrophilizing agent to the nonwoven fabric.

If the apparent thickness of the non-woven fabric is large, it is soft, and if the pitch of the unevenness and the size of the recesses are not made too thick, a fine-textured fiber feel can be obtained.

The bulkiness of the nonwoven fabric in the present invention is 100% or more, preferably 105-400%, more preferably 110-300%, particularly preferably 120-200%. When the bulk rate is high, the thickness of the load will become smaller as the load decreases, and the cushioning properties of the non-woven fabric will be improved.

The change in the thickness of the spunbonded nonwoven fabric in the present invention with respect to load is shown in Fig. 5 and Fig. 6 . It can be said that the spunbonded nonwoven fabric of the present invention has a large thickness and bulkiness under various loads, and has good compressibility under loads. Therefore, when the spunbonded nonwoven fabric in the present invention is used as the surface layer of a disposable diaper, the thickness will not decrease with the passage of time, and the soft and bulky characteristics will continue to be effective in the use of the diaper. Also very good. In addition, there is little drop in thickness in the state of the net, and a good effect can be obtained because the bulk rate is high for the return of liquid from the absorbent body.

The method of applying the concave or convex embossing pattern of the non-bonded non-woven fabric, such as generally having a concave, convex or concave-convex pattern on the surface, between the rollers where the two just overlap, with a concave-convex pattern on one surface Pressing between the rollers and flexible rollers, or processing between the plates, as a special method, there is also the following method: the cloth is forcibly overfed at a certain ratio between the rollers with a narrow gap, and the Embossed in small ruffles.

Fig. 4 is an example of applying concave-convex deformation by passing between two rollers that have circular concave-convex patterns on the surface and coincidently overlap.

In the conditions of embossing, special attention should be paid to the temperature during processing and the pressure applied to the nonwoven fabric. The temperature during treatment can be normal temperature, and if necessary, it can also be heated for plasticization to facilitate embossing, or for the purpose of improving shape stability, the temperature can be increased within the range that does not cause fiber bonding and setting . For example, in the case of a polypropylene nonwoven fabric, the range of 30-110° C. is preferable. The embossing pressure varies depending on the temperature, and of course it must be set to a pressure that allows sufficient embossing. In addition, since embossing deforms the fiber cross-section of the compressed part, and the deformation effect of this part produces better flexibility, it is also very effective to further apply high-pressure treatment. Of course, it is necessary to employ conditions under which temporary fixation and thermocompression welding between fibers in the compressed portion do not occur. For example, in the case of a polypropylene nonwoven fabric, the range of 20-150 kg/cm is preferable.

In the spunbonded nonwoven fabric of the present invention, it is preferable that the non-bonded fiber high-density region recesses are embossed on one surface of the nonwoven fabric, and the non-bonding high-density fiber form the convex parts on the opposite surface. For example, when a high-density region of continuous recesses is formed on one surface, it is preferable to form a convex shape protruding from other regions so that the high-density region becomes a convex portion on the other surface. This point is very important to apply the hydrophilizing agent to a specific portion while making the apparent thickness of the entire nonwoven fabric more than the thickness of the web.

The hydrophilic treatment of the spunbonded nonwoven fabric of the present invention uses a common diluted hydrophilizing agent solution, and existing methods such as soaking, spraying, and coating (roll coating, gravure coating, die coating, etc.) can be used. Methods. After applying the hydrophilizing agent, the non-woven fabric is dried using a drying device such as hot air or a hot roller.

In the hydrophilization treatment, the adhesion distribution of the treatment agent is different between the high-density area applied first and the other parts. When the treatment agent is applied, the liquid appears to be more concentrated in the low-density and rougher parts of the fiber, and as the nonwoven dries, the liquid moves to the easier-to-dry parts. Therefore, when the thickness of the nonwoven fabric is thin in the high-density region of non-bonded fibers, the treatment agent adheres more and the liquid passes through easily. In addition, since the permeated liquid is not easily compressed and bulky in the low-density area, it leaves the absorbent layer and is difficult to rewet. In this way, the hydrophilizing agent becomes mainly rich in the high-density region of non-bonded fibers, and the spunbonded nonwoven fabric of the present invention can obtain the characteristic improvement of liquid permeability, improvement of rewetting property, and liquid flow. Improved effect.

Corona treatment, plasma treatment, etc. are preferably performed before the hydrophilization treatment, so that the degree of hydrophilization can be increased. Treatment such as corona treatment can be a general treatment for improving wetting characteristics as a pre-treatment for printing. Nonwovens are processed through them. The surface tension of the treated surface varies depending on the required wettability and treatment conditions, but it is preferable to set the discharge conditions so that the surface tension is 37-40 mN/m. In addition, when the corona discharge treatment is applied, since the wettability of the nonwoven fabric itself is different, the application amount of the hydrophilizing agent is of course adjusted in order to obtain the necessary performance. When the surface tension of the non-woven fabric is in the range of 37-40mN/m, the affinity between the hydrophilizing agent and the surface fibers of the non-woven fabric is significantly improved, and the hydrophilizing agent can be applied uniformly at a low concentration . In the present invention, the application of the hydrophilizing agent is preferably performed after the roughening of the non-bonding fiber region, and there is no problem in applying it before the roughening.

When the present invention treated with a hydrophilizing agent is used for a spunbonded nonwoven hygienic material, the performance or the method of use can be selected according to the level of characteristics of the hygienic material purpose, but it is also different from the nonwoven fabric. It is related to the difference in touch between the surface and the inside of the cloth. Although the fiber-high-density areas in the embossed concave and convex patterns are not connected to each other, they have been fixed compared with others. Therefore, when used as the surface layer of a diaper, the preferred method is to arrange it on the surface of the non-woven fabric. On the side of the absorbent body on the back side that does not come into direct contact with the skin, when paying attention to hydrophilicity, the high-density area is arranged on the side of the surface layer that contacts the skin.

The spunbonded nonwoven fabric in the present invention uses a laminated body with more than two layers in the structure of the nonwoven fabric, and the laminated body with more than two layers is composed of at least one layer of long wire mesh and at least one layer of meltblown mesh layer. accumulated.

In this case, the fibers used for the nonwoven fabric can use the above-mentioned fiber materials. Mixtures of these composite fibers, mixed fibers, and fibers having other special functions can also be used as needed. Even materials that differ between layers between the filament webs are effective, and materials that differ between the filament web and the meltblown web are also possible. Materials with affinity to water, such as polyester fibers and polyamide fibers, need to be treated or added with water repellents such as silicon, fluorine, or waxes as needed from the perspective of water repellency. , for improvement.

The non-woven fabric needs to have strength that can cope with body movements during use. From the viewpoint of productivity, it is preferable to laminate at least one layer of filament web and at least one layer of melt-blown fiber web. body, forming a non-woven fabric by connecting them continuously. The layered structure can be only the lamination of the filament web and the melt-blown fiber web, but in order to make up for the weak surface strength of the melt-blown fiber web, usually a layer of melt-blown fiber web layered between the filament web layers is used. substance, and it is advantageous to set the individual layers as multilayers. In addition, it may be a material in which each net is connected and laminated.

The filaments that make up the spunbonded nonwoven fabric are 0.5-5dtex, and because of the long fiber length, they have practical strength and good air permeability, and unlike wet or dry manufacturing, the fibers are directly processed without oil treatment. Since it is made into a sheet, it can take advantage of properties such as water repellency unique to fibers.

Melt-blown fiber web, as described in the Publication No. 56-3351, USP3,978,185, USP3,825,380, etc., is formed by fine fibers of 1-6 μm and has good coverage, for example, it has better coverage in polypropylene materials. Water-repellent, waterproof effect. Since the melt-blown fiber web is a fine fiber, the crystal orientation is lower, so it is easier to connect than the filament web. However, when it is reversed and used alone, even if it is connected, its strength is weak, and it becomes a material with a hard touch like paper. Therefore, by laminating the melt-blown net and the filament net, various shortcomings can be made up for, and the strength in actual use is relatively high, and the coverage, water repellency and water resistance are good.

For the connection and fixation of the web, in order to maintain the strength and softness of the nonwoven fabric and the feel of the fiber itself, it is preferable to perform connection by partial thermal compression welding using a thermal embossing roll. The thermocompression welding area ratio in partial thermocompression welding is preferably 5 to 40%, more preferably 5 to 25%, from the viewpoint of maintaining strength and flexibility. Partial thermocompression welding can be carried out by ultrasonic method or by passing the net between heated embossing rollers. In this way, the surface and the inside become integrated, and the floating and sinking patterns such as needle point, ellipse, rhombus, and rectangle are scattered on the surface. Spin the entire surface of the fabric. Of course, the thermocompression-welded portion is crimped and takes the form of a film, but the fibers around it, especially the filament web, maintain the unique feel of the fibers used.

In the conditions of connecting the filament web layer, the melt-blown fiber web layer is extremely thin, and according to the characteristics of its fiber formation, it becomes a paper-like touch by heating, and the non-woven fabric as a whole becomes a substance with paper-like hardness . In addition, the thickness of the non-woven fabric that has undergone partial thermocompression welding changes according to the fiber structure, embossed shape, and configuration, resulting in a unique connection effect of the melt-blown fiber web layer, and the thickness becomes thinner without bulkiness. As a bulky improvement method, there is a method of opening holes and shaping and fixing as described in the existing technology, but it is not the same as the present invention, which will be made of at least one layer of filament web and at least one layer of melt-blown fiber web. The laminate composed of more than two layers is integrated on the surface through discontinuous partial heat-press welding parts scattered on the surface, and the obtained non-woven fabric obtains bulkiness or Softness, and did not improve the connection effect of the melt-blown fiber web layer.

The gist of the present invention under the design of the laminated melt-blown fiber web in the non-woven fabric structure is: for the laminated body consisting of at least one layer of filament web and at least one layer of melt-blown fiber web laminated by spreading on The non-woven fabric in which the non-continuous part of the surface is thermocompression-welded and the front and back are integrated is further processed by embossing or the like to give non-bonding concave-convex deformation, so that the fibers of the dispersed thermocompression-welded part are partially bonded and surfaced. The fibers in the non-bonded concave-convex part of the other parts have the soft touch of the fibers themselves.

In the melt-blown fiber web layer, even if it has a connection effect to some extent, it is in a temporarily connected state unlike the thermocompression welding part, and it is a relatively hard and rough substance obtained by welding the composite fibers through heat treatment for connection. Totally different. In addition, sufficient bulkiness can be obtained by applying a non-cohesive uneven deformation force to the fibers having a degree of freedom to form a partially deformed (stretched) fiber layer. When a load is applied, unlike the original fiber layer, it has the property that it is not easy to compress. That is, easy-to-bend lines appear and have flexibility and bulkiness (thickness).

FIG. 6 is a graph showing changes in thickness of nonwoven fabrics with respect to load in Example 8 and Comparative Example 8. FIG. In the present invention, it is a nonwoven fabric that is not easily compressed even when a load is applied, and is a nonwoven fabric that does not cause a decrease in bulkiness even under a load.

The concavo-convex embossing pattern of the high-density fiber region composed of non-bonding fibers applied to the spunbonded nonwoven fabric in the present invention is a non-bonding depression of any shape partially inconsistent with the pattern of the partially bonded bonding part or The relationship between the shape, size, depth and joint pattern of convex deformation, concave or convex is very important for the softness effect. For example, the shape can be a straight line, a curve, an edge, a circle, a pear-skin shape, other connected or discontinuous shapes, but from the perspective of the softness effect, it is preferable that the depth of the depression or protrusion is 0.2-5mm, and the more concave-convex The deeper the effect, the better.

The size of the pressing surface of the discontinuous patterns is preferably 0.1-5 mm, and the pitch of the concave or convex parts is preferably 0.5-5 mm. In the patterns of Fig. 1(I) and Fig. 3 , the embossed pattern scattered with convex parts is extruded to form discontinuously scattered concave parts in the high-density area. In addition, by pressing the continuous embossing pattern of the raised pattern shown in FIGS. 2 and 4 , the concave portions in the high-density region are continuous and the number of fiber layers in the non-extruded portion increases. The deformation pitch produced by the continuous embossing pattern is preferably 1-5 mm, and the size and width of the concave part are preferably lines or dotted lines of 0.02-3 mm.

In these spunbonded non-woven fabrics with embossed concave-convex patterns, part of the hot-press fusion part is configured as a high-density region of non-bonded fibers and a low-density region of non-bonded fibers through a pattern that is inconsistent with the embossed concave-convex pattern. (Refer to Figure 1-4 C).

The area ratio of the concavo-convex pressed portion in the non-bonding fiber high-density region is preferably 5-40%, more preferably 5-25%, from the viewpoint of obtaining good softness and fiber touch. In consideration of actual use, the larger the apparent thickness, the softer it is, but when the deformation distance and the size of the concave portion are not too large, a compact effect can be obtained, and the bulking rate before and after applying non-bonding deformation is preferably 100% or more , more preferably 105% or more, particularly preferably 130% or more.

The method of applying concave or convex patterns generally includes: for example, the surface of the spunbonded non-woven fabric applied by partial thermal fusion and thermal embossing has concave, convex or concave-convex patterns, between the rollers that are just fitted on both sides, Pressing is performed between a roll with concave or convex patterns on one surface and flexible rolls such as paper rolls, rubber rolls, and resin rolls, or processing between plates. As a special method, there is also a method of forcibly overfeeding the cloth at a certain ratio between rollers having a narrow gap, and embossing in the form of small creases.

In the conditions of embossing, special attention should be paid to the temperature during processing and the pressure applied to the cloth. Especially in the form of a nonwoven fabric comprising a layer of meltblown fibers according to the invention, it is easier to receive deformation effects than a nonwoven fabric having only a filament web. Therefore, the bonding effect of the melt-blown fiber layer can be suppressed in terms of flexibility, so the processing temperature is preferably set lower than that of the filament web alone, and can be appropriately set according to the fiber material. For example, when polypropylene is used as a material, the temperature is preferably set to 60° C. or lower, more preferably 50° C. or lower, and active cooling is also effective if necessary.

On the other hand, it is also possible to increase the temperature to perform plasticization in the range where fiber bonding and setting do not occur to facilitate embossing and maintain shape stability. The pressure at the time of processing varies depending on the temperature, and can be set to a pressure that sufficiently deforms. In addition, it is also effective to further perform high-pressure treatment in order to obtain better flexibility by deforming the fiber cross-section of the compressed portion by additional deformation. Of course, it is necessary to take sufficient care not to temporarily fix the fibers of the compressed portion or to prevent thermocompression welding.

As a preferred aspect of the present invention, it is preferable that one surface is a high-density region of pressed protrusions, and the opposite surface forms a high-density concave portion. That is, for example, when a continuous portion (high-density region) is formed on one surface, it is preferable to make the high-density region protrude from other regions in order to make the high-density region a convex portion on the other surface. It is important to set the apparent thickness of the entire nonwoven fabric to be equal to or greater than the thickness of the web. By forming such high-density to low-density regions without connection, the cloth becomes thick as a whole or is easily bent by bending force, so it becomes a soft material, which has a thin, flat surface, and a completely different touch from paper. In order to enhance such processing effects, multi-layer processing can be performed.

Depending on the necessity of the nonwoven fabric of the present invention, various treatment agents such as antistatic agents, softening agents, hydrophilizing agents, and lubricants may be applied.

When the spunbonded nonwoven fabric of the present invention is used for sanitary materials, the performance to be imparted or the method of use are selected according to the level of properties intended as sanitary materials. It is also necessary to consider the difference in touch between the front and back of the non-woven fabric. That is, although the compressed high-density region is not connected, it is fixed compared to others, so it is preferable to arrange this surface on the side that does not directly contact the skin, or to arrange it in consideration of the use of convex parts.

The low-temperature embossing process in the present invention is preferably carried out in-line in the production process of spunbond nonwoven fabrics from an economic point of view, but may be introduced into a part of the production and processing line of diapers for offline processing.

Description of drawings

Fig. 1 (I) is the schematic diagram of the planar structure of the spunbonded non-woven fabric of the present invention, and Fig. 1 (II) is that the non-woven fabric structure is only fixed by the pattern of the partial hot-press fusion fiber region, and the non-bonding of the non-woven fabric surface A schematic cross-sectional view of a spunbonded nonwoven fabric without uneven processing in the fiber region, and FIG. 1 (III) is a schematic diagram of a cross-sectional structure of a spunbonded nonwoven fabric according to the present invention.

Fig. 2 is the concave lattice pattern of the high-density region of the continuously connected non-bonding fibers in the spunbonded nonwoven fabric of the present invention, that is, the first face of the nonwoven fabric structure, and the continuously connected concave lattice pattern is set. In the embodiment, the schematic diagram illustrating the pattern of a part of the thermocompression-welded fiber domain is omitted.

In FIG. 3 , the high-density region depression pattern of non-bonding fibers constitutes a non-continuous spunbonded nonwoven fabric of the present invention, and the illustration of the region pattern of thermocompression-welded fibers is omitted like the example in FIG. 2 .

In FIG. 4 , the high-density area concave tortoise shell pattern of non-bonding fibers continuously arranged constitutes the spunbonded nonwoven fabric of the present invention, and the illustration of the heat-press-welded fiber area pattern is omitted like the example in FIG. 2 .

5 is a schematic diagram showing the relationship between various loads and thickness of the spunbonded nonwoven fabrics in Example 1 and Comparative Examples 1, 5 and 6 of the present invention.

Fig. 6 is a graph comparing the thicknesses of the spunbonded nonwoven fabrics of Example 8 of the present invention and Comparative Example 8 under various loads.

Fig. 7 (I) is a schematic view of the structure of a spunbonded nonwoven fabric as an example of the present invention, and Fig. 7 (2) is a spunbonded nonwoven fabric before implementing concavo-convex processing to the region of non-bonded fibers in Fig. 7 (1). An enlarged view of a microscope photograph of the structure of the cloth.

Fig. 8 (I) is a schematic view of the structure of the spunbonded nonwoven fabric of the present invention with a melt-blown fiber web added as another example, and Fig. 8 (II) is to apply concavo-convex to the non-bonded fiber region of Fig. 8 (I) An enlarged view of a microscope photograph of the structure of the spunbonded nonwoven fabric before processing.

Detailed ways

The present invention will be further described below through examples and comparative examples.

First, measurement methods and evaluation methods will be described.

(1) Weight per unit area of non-woven fabric

Select multiple pieces of 10cm square non-woven fabric, and its weight is represented by the weight per ^1m2 .

(2) Thickness of non-woven fabric

Using a compression elasticity testing machine E-2 type manufactured by Zhongshan Electric Industry Co., Ltd., it was measured under each load of 1.3, 10, 37.5, 50, and 100 g/cm ² in a measurement area of 4 cm ² .

(3) Bulk rate of non-woven fabric

The rate of change in the thickness (under a load of 10 g/cm ² ) of the nonwoven fabric before and after applying the high-density region of non-bonding fibers of the present invention was taken as the bulk rate.

(4) Strength of non-woven fabric and stress at 5% elongation

A test piece with a width of 3 cm and a length of 20 cm was subjected to a tensile test with a grip width of 100 mm and a test speed of 300 m/min using a universal tensile machine manufactured by Shimadzu Corporation, and the longitudinal and transverse strengths and 5% elongation were measured. of stress.

(5) Bending softness of non-woven fabrics

As an index showing flexibility, it is represented by bending flexibility measured by the following method.

The measurement method is to leave 1cm remaining at the end of one measurement direction of the test material, press down the full width of the test material with a ruler in the right angle direction, and place no creases on the other end of the test material. At the end pressed down by the ruler. In a state where the end portion on the side pressed down by the scale is pressed down by hand, the scale is moved in the ring while sliding the scale on the test material.

The point at which the ring extends under the reaction force of the test material is taken as the end point, and the length from this point to the end of one side of the ring is taken as the critical length (mm), expressed as the average value in the table and back. The shorter the softer.

(6) Measuring surface for water permeability

Water permeability is to use non-woven fabric as the surface layer of disposable sanitary materials, and use the side used for the surface as the measurement surface of water permeability. "Above" or "below" shown in the "Water Permeability Measurement Surface" column of Table 1 indicates the properties for one side of the surface, respectively.

(7) Instant water permeability

Set 10 overlapping sheets of toilet paper as an absorber on a measuring device (approximately 800 g, a 10 cm square with a hole in the center of 25 mm in diameter, two electrodes placed in the center and connected to a timer), and the measurement is to put the test cloth A 10 cm square (above) was placed between the absorber and the measuring device, and 1 drop (0.1 cc/drop) of physiological saline was dropped from a dropper 15 mm above the cloth. The time from the start of dripping to the end of passing through the cloth surface was measured with an electrode, and it was regarded as the instantaneous water penetration rate (seconds).

(8) 5cc water permeability (seconds/5cc), moisture return (g)

In order to keep the characteristics of the absorber constant, specific filter paper ("939" manufactured by Eaton Dikeman Co., Ltd., 10 cm square x 3 sheets stacked) was placed under the measuring device (the same as the instantaneous water permeability measuring device in (6)) as the absorbing body. A test cloth (10 cm square) was placed on this absorber. First, drop 5cc of artificial urine from the upper 25mm. Artificial urine is a substance that adds a non-ionic active agent to physiological saline and adjusts it to 45±3 dyne/cm (mN/m), and the dropping speed is 3.3 seconds/25cc . The time from the start of dripping to the end of passing through the cloth surface was measured with an electrode, and it was regarded as a 5 cc water penetration rate (second/5 cc).

Next, artificial urine is added directly, and in order to keep the amount of liquid contained in the absorber constant, the total amount of liquid is about 4 times the weight of the absorber. In this state, a load of 800 g/10 cm square was applied from the test cloth for three minutes to stabilize the liquid distribution in the absorbent body. Next, overlay the filter paper weighed in advance on the test cloth ("631" manufactured by Eaton Dikeman Co., Ltd. 12.5 cm square x 2 sheets), and quickly apply 3600g/10 cm square for two minutes (equivalent to the load applied to infant diapers) , Measure the weight increase of the filter paper as the rewetting amount (g).

(9) Liquid flow

10 sheets of toilet paper were placed on a 45-degree inclined table as an absorber, the test cloth was adhered to it, and 1 drop (0.1 cc/drop) of physiological saline was dropped from a dropper 15 mm above the cloth. The flow length from the dripping portion on the cloth surface to the end of passage was measured as liquid flow (mm).

(10) Durable water permeability

10 sheets of toilet paper were placed on a flat surface as an absorber, and the test cloth was attached thereto. One drop (0.1 cc/drop) of physiological saline was dropped from a dropper 15 mm above the cloth. What absorbed the dripping liquid within 2 seconds was regarded as permeation. After the surface was dry, 1 drop was dropped again on the same position, and the second test was carried out. And repeat the same action for the third trial. The same test material was tested at 10 to 40 locations, and the ratio of the number of penetration to the number of drops was defined as the durable water permeability (%).

(11) Fineness

The diameter of the fiber constituting the nonwoven fabric was measured with a microscope (Keyence Corporation high-magnification microscope VH-8000), and the fineness (dtex: weight of filament 10,000 m long) calculated from the density of the fiber polymer was used as the circular cross-section fiber. )express. In addition, the fineness of the meltblown fiber web is expressed by fiber diameter.

(12) Softening rate of non-woven fabric

The rate of change in softness in the longitudinal direction (after treatment/before treatment) before and after application of the high-density region of the non-bonded fiber of the present invention was defined as the softening rate. The softening rate indicates that the smaller the numerical value, the greater the softening effect.

(13) Water pressure resistance

The scale indicating the fine density and water resistance of non-woven fabrics is expressed by water pressure resistance. A test material piece (20 cm square) was selected, and it measured based on JIS-L-1092.

(Example 1, Example 2)

Using titanium oxide-containing polypropylene (MFR = 40 measured under the conditions of Table 1 of JIS-K7210) as a raw material, long fibers melted and extruded from a nozzle with a circular cross-section are cooled from the side near the spinneret. Traction and pulling devices such as air aspirators are used for traction. The filaments coming out of the pulling device are opened by the charging device, and then collected as a net on the moving metal mesh conveyor.

The web is passed between the embossing rolls/flat rolls heated to 135°C, and a needle point pattern (area ratio of about 7%) arranged in a zigzag pattern (area ratio of about 7%) is formed in a circle with a diameter of 0.43 mm and an inclination of 45° and an inclination pitch of 1.5 mm. Heat press welding, thus obtaining a non-woven fabric with scattered patterns of pinpoints.

The constituent fibers of the obtained spunbonded nonwoven fabric are circular cross-section filaments of 2.8dtex (Example 1) and 2.0dtex (Example 2), and the partial hot-press welding area ratio is 70%, and the weight per unit area is 20g/ m ² .

Pass the non-woven fabric through a continuous linear honeycomb pattern (depressed tortoise shell pattern: refer to Figure 4) with a side of 0.9mm and a line width of 0.1mm (the pressing area ratio is 12.5%, and the pattern pitch is 2.8mm in the vertical direction and 3.2mm in the horizontal direction). mm, depth 0.7mm) between an embossing roller (100°C) and a rubber roller with a surface hardness of 50 degrees (JIS-A hardness), the pattern is embossed with a linear pressure of 100kg/cm. The periphery of the tortoise shell is pressed down to obtain a soft non-woven fabric with a high-density area and a raised central portion.

Apply 0.45wt% of hydrophilizing agent mainly composed of polyethylene glycol propylene glycol block polymer polyether and polyether modified siloxane to the non-woven fabric by gravure, as a hygienic material Use non-woven fabric. The performance evaluation results of non-woven fabrics are shown in Tables 1 and 2.

Disposable diapers manufactured by disposing low-density regions (embossed dimpled surface) of non-bonding fibers on the surface of the nonwoven fabric on the skin side of the surface layer are comparable to diapers made of conventional nonwoven fabrics. Compared with that, the fiber layer between the high-density areas is raised, it is softer, and the rewetting property is improved, and it is a dry non-woven fabric with a soft touch. Example 2 of fine dtex is a smoother object with softness.

(Example 3, Example 4)

Except that the non-combining lower pressure embossing pattern is discontinuously as the discontinuity of embodiment 1 as the raised tortoise shell pattern (0.45mm on one side, 25% of the pressing area ratio, pattern spacing vertically 2.8mm, horizontal 3.2mm, deep 0.6mm), other are all identical with embodiment 1, thereby obtain 2.8dtex, the weight per unit area is the nonwoven fabric of the present invention of 20g/m ² . The evaluation results of non-woven fabrics are shown in Tables 1 and 2.

The nonwoven fabric was used as the surface layer, and in Example 3, the continuous protrusions of the low-density region of the nonwoven fabric (the surface of the nonwoven fabric) were used on the skin side of the surface layer, and in Example 4, the nonwoven fabric was used instead. The non-continuous debossed pattern surface of the high-density area on the back is used for the top layer to make disposable diapers. As in the Examples, the softness was better than that of the conventional nonwoven fabric, and the rewetting property was also good. In addition, the surface layer (Example 4) of this nonwoven fabric was turned upside down, and the high-density region was raised in the form of dots, and it had a dry touch in addition to a smooth surface.

(Example 5)

Except for the non-combined embossed pattern as a discontinuously scattered concave grid pattern (0.3mm×0.7mm on one side, 22% pressing area ratio, 0.6mm deep) and passing through a roller containing a concave grid pattern that matches the pattern Except for the combination, the others are the same as in Example 1, thereby obtaining a nonwoven fabric of the present invention with 2.0 dtex and a weight per unit area of 18 g/m ² . The evaluation results of non-woven fabrics are shown in Tables 1 and 2.

A disposable diaper was produced by making the surface of the nonwoven fabric with the continuously raised surface of the low-density region (the surface of the nonwoven fabric) facing the skin surface of the top layer. Like Example 1, compared with the conventional nonwoven fabric, it is better in softness and has good rewetting performance.

(Example 6 and 7)

Before applying the hydrophilizing agent, carry out corona treatment, and the condition of corona treatment is to carry out the discharge capacity of 30W under the atmosphere of room temperature 22 ℃? Min/m ² (discharge degree 2.2W/cm ² ), the result is that the surface tension of the nonwoven fabric is 37mN/m, except that 0.3wt% of the hydrophilizing agent is attached in consideration of improving wettability by corona treatment Except that, the nonwoven fabric for hygiene materials of this invention was manufactured similarly to Example 1 and Example 3, and Examples 6 and 7 were obtained. The disposable hygienic material using the obtained non-woven fabric as a surface layer is softer and has less adhesion of the hydrophilizing agent than the material composed of the existing non-woven fabric, but it has good properties like Examples 1 and 3. With excellent water permeability and less treatment agent, a good non-woven fabric with dry and soft touch can be obtained.

(Comparative Examples 1, 2, 3 and 4)

In Examples 1, 2, 5, and 7, cases where a hydrophilizing agent was applied without performing non-binding pressing were referred to as Comparative Examples 1, 2, 3, and 4, respectively.

(comparative examples 5 and 6)

As a comparison of the surface layer, a staple fiber point-bonded nonwoven fabric (19 g/m ² : Comparative Example 5) and a two-component staple fiber air-through nonwoven fabric (89 g/m ² : Comparative example 6), its result is as shown in table 1 and table 2.

Table 1 Material Fineness (dtex) Embossed embossed pattern non-woven fabric Partial thermocompression welding area ratio% Concave or convex area ratio % corona treatment Attachment of hydrophilizing agent superficial skin side Water permeability measurement surface Weight per unit area of non-woven fabric (g/m ² ) Thickness of nonwovens under various loads Bulk rate of non-woven fabric (%) above (table) Below (in) 1.3g/ ^cm2 10g/ ^cm2 37.5g/ ^cm2 50g/ ^cm2 100g/ ^cm2 Example 1 PP 2.8 Debossed tortoise shell pattern Low density raised (non-continuous) High Density Raised (Continuous) 7 12.5 none have surface surface 20 0.36 0.26 0.21 0.19 0.16 124 Example 2 PP 2.0 Debossed tortoise shell pattern Low density raised (non-continuous) High Density Raised (Continuous) 7 12.5 none have surface surface 20 0.33 0.22 0.17 0.16 0.14 116 Example 3 PP 2.8 Raised tortoiseshell pattern Low Density Raised (Continuous) High density bumps (non-continuous) 7 25 none have surface surface 20 0.35 0.23 0.17 0.16 0.12 110 Example 4 PP 2.8 Raised tortoiseshell pattern Low Density Raised (Continuous) High density bumps (non-continuous) 7 25 none have inside inside 20 0.32 0.21 0.17 0.16 0.13 111 Example 5 PP 2.0 Raised check pattern Low Density Raised (Continuous) High density bumps (non-continuous) 7 twenty two none have surface surface 18 0.31 0.24 0.19 0.15 0.13 133 Example 6 PP 2.8 Debossed tortoise shell pattern Low density raised (non-continuous) High Density Raised (Continuous) 7 12.5 have have surface surface 20 - 0.26 - - - 124 Example 7 PP 2.8 Debossed tortoise shell pattern Low Density Raised (Continuous) High density bumps (non-continuous) 7 25 have have surface surface 20 - 0.23 - - - 110 Comparative example 1 PP 2.8 none have - 20 0.29 0.21 0.17 0.15 0.12 - Comparative example 2 PP 2.0 none have - 18 0.25 0.19 0.15 0.14 0.12 - Comparative example 3 PP 2.0 none have - 18 0.23 0.18 0.14 0.13 0.12 - Comparative example 4 PP 2.8 have have - 20 - 0.21 - - - - Comparative Example 5 PP (2.2) none have - 19 0.27 0.16 0.13 0.12 0.11 - Comparative example 6 PP/PE (2.3) none have - 18 0.61 0.28 0.18 0.17 0.12 -

Table 2 Tensile strength of non-woven fabric (N/3cm width) Stress at 5% elongation of non-woven fabric (N/3cm width) Softness of non-woven fabric (mm) Water permeability Remark vertical horizontal vertical horizontal vertical horizontal Instant water permeability (seconds) 5cc permeable (seconds) Rehumidity (g) Liquid flow(mm) Durable water permeability (permeability) 1 time 2 times 3 times Example 1 28.9 7.7 12.5 1.3 78 47 0.12 3.0 0.6 26 100 100 60 Example 2 28.5 7.2 12.0 1.3 76 50 0.12 3.1 0.8 28 100 100 60 Example 3 28.3 6.8 11.6 1.1 79 49 0.11 3.2 0.8 30 100 100 60 Example 4 28.8 7.5 11.5 1.3 77 46 0.11 3.2 0.8 27 100 100 60 Example 5 27.1 6.5 11.0 1.1 78 50 0.11 3.2 0.9 28 100 100 60 Example 6 - - - - - - 0.12 3.2 0.9 twenty one 100 100 80 Example 7 - - - - - - 0.11 3.5 0.7 27 100 100 60 Comparative example 1 32.6 7.6 13.3 1.5 87 57 0.13 3.2 1.0 34 100 100 40 Comparative example 2 31.9 7.4 15.3 1.5 85 52 0.13 3.2 1.3 36 100 100 40 Comparative example 3 29.9 7.1 12.8 1.4 83 50 0.13 3.3 1.3 35 100 100 40 Comparative example 4 - - - - - - 0.11 3.2 1.7 twenty two 100 100 70 Comparative Example 5 - - - - - - 0.24 2.8 0.5 30 100 0 0 Short fiber point connection Comparative Example 6 - - - - - - 0.10 2.7 0.1 20 100 40 0 Short fiber hot air bonded

From the results of Table 1 and Table 2, it can be found that the nonwoven fabrics in the examples are bulkier than the nonwoven fabrics in the comparative examples, have less thickness change under load, have softness, and are water permeable in an instant. Good water permeability, such as moisture resistance, liquid fluidity, and water permeability durability.

The non-woven fabrics for hygienic materials of the present invention shown in Table 1 and Table 2 have good bulkiness, the bulkiness rate is more than 110%, the thickness change is small when loaded, the compressibility to load is good, and it is soft. , At the same time, it has good water permeability and water permeability durability.

(Example 8, Example 9)

Using polypropylene (MFR = 40 measured under the conditions of Table 1 of JIS-K7210) as a raw material, the long fibers melted and extruded from a nozzle with a circular cross section are cooled from the side near the spinneret, while using an air aspirator. Wait for the pulling device to pull. After being opened by the electrification device, the filaments coming out of the pulling device are collected as long wire webs (2.8dtex (Example 8) and 1.2dtex (Example 9), respectively 6.5g/m ² ) to the moving on the metal mesh conveyor.

Two melt-blown fiber webs made of polypropylene (MFR = 700 measured under the conditions of Table 1 of JIS-K7210) are laminated on this web, and high-pressure, high-temperature air is blown from two slits near the output nozzle. (Fiber diameter: 1.8 μm, 1 g/m ² ). Further, the filament net produced in the same manner as above was collected and laminated thereon to form a laminated net (15 g/m ² ). Make the web pass between embossing rolls/flat rolls heated at 130°C, pass through an elliptical pattern with a long diameter of about 0.9mm, a short diameter of about 0.5mm, and an area of ^0.36mm2 inclined at 30°, with a configuration of about 3mm in length , A 1.7m wide zigzag twill pattern (crimping area ratio 15%) is partially thermocompressed and welded between heated embossing rolls to obtain a scatter pattern (twill pattern) with elliptical dots of non-woven fabrics.

This nonwoven fabric was passed through an embossing roll (40° C.) with a continuous linear honeycomb pattern (depressed tortoise shell pattern) with a side of 0.9 mm and a line width of 0.1 mm (down pressure area ratio 12.5%, depth 0.7 mm) Between the rubber roller with a surface hardness of 50 degrees (JIS-A hardness), the pattern is pressed down with a linear pressure of 100kg/cm. The periphery of the tortoise shell is pressed down to obtain a soft non-woven fabric with a high-density area and a raised central portion. The performance evaluation results of non-woven fabrics are shown in Table 1 and Table 2. The nonwoven with a filament web fineness of 1.2 dtex (Example 9) is a softer nonwoven in addition to the smooth feel of the surface fibers.

Disposable diapers produced by using these nonwoven fabrics as three-dimensional gathers are softer and have a better thickness than conventional disposable diapers made of nonwoven fabrics that have not been softened. In addition, the disposable diaper in which the microporous PE film is laminated to the non-woven fabric as the back layer has a soft touch and sufficient strength for practical use that cannot be obtained by the existing laminated non-woven fabric without softening treatment. Strong surface strength.

(Example 10, Example 11)

In order to obtain non-cohesive concavo-convex deformation, the depressing embossing pattern is used as the discontinuously scattered tortoiseshell embossing pattern (0.45 mm on one side, 25% of depressing area ratio, 0.6 mm in depth) opposite to Example 8, and in addition In the same manner as in Example 8, nonwoven fabrics having a weight per unit area of 15 g/cm ² (Example 10) and 17 g/cm ² (Example 11) were obtained. The performance evaluation results of non-woven fabrics are shown in Table 3 and Table 4.

Disposable diapers were produced using the nonwoven fabric as three-dimensional gathers. Similar to Example 8, the softness was better and the thick feeling was better than the disposable diaper comprised of the conventional nonwoven fabric which was not softened. And, the surface of the non-woven fabric is turned upside down, and the object laminated with the microporous PE film as the back layer is an object with a high-density area of non-bonded fibers, which has a good touch in addition to a smooth and dry surface.

(Example 12)

In order to obtain non-combining concave-convex deformation, the pressed embossed pattern is used as a discontinuously scattered raised grid pattern (one side 0.3mm×0.7mm, the pressed area ratio is 22%, and the depth is 0.6mm). Between the combination of rolls with a concave grid pattern, except that it is the same as in Example 8, a nonwoven fabric with a weight per unit area of 15 g/cm ² can be obtained. The performance evaluation results of non-woven fabrics are shown in Table 3 and Table 4.

This nonwoven fabric was laminated with a microporous PE film and used as a back sheet to produce a disposable diaper. As in Example 8, compared with the conventional nonwoven fabric, the softness is higher and the feeling of thickness is better.

(Example 13)

In order to obtain non-combined concave-convex deformation, the pressed embossed pattern is used as a continuous oblique raised pattern (0.2mm on one side, 0.5mm interval, 29% pressed area ratio, 0.6mm deep), and the surface hardness is 60 degrees. (JIS-A hardness) and a combination of rubber rollers with a thickness of 15 mm were the same as in Example 8 except that a nonwoven fabric with a weight per unit area of 17 g/m ² was obtained. The evaluation results of non-woven fabrics are shown in Table 3 and Table 4.

The non-woven fabric has oblique curvature, and has higher softness and better thickness than the non-woven fabric before softening treatment.

(Example 14)

In addition to polypropylene (JIS-K7210 Table 1 measured under the conditions of Table 1 = 40) of the base polymer, a filament net (1.8dtex, 6.5g/ m ² ), the others were the same as in Example 8, and a nonwoven fabric with a weight per unit area of 15 g/m ² was obtained. The performance evaluation results of non-woven fabrics are shown in Table 3 and Table 4.

The surface touch of the non-woven fabric has the same supple feeling as polyethylene, and has better softness and good thickness than the non-woven fabric before softening treatment.

(Example 15)

Except that in Example 8, the filament mesh layer on one surface was set to a 1.2dtex (3.3g/m ² ) mesh on the outside and a 2.8dtex (3.3g/m ² ) mesh on the inside, the other 8, a non-woven fabric with a weight per unit area of 15 g/m ² can be obtained. The obtained nonwoven fabric was a nonwoven fabric with a smooth surface layer and a sense of thickness.

(embodiment 16, embodiment 17)

Polyethylene terephthalate (viscosity ηsp/C = 0.75) and nylon 6 (relative viscosity ηrel = 2.7) were used as base polymers for filament webs, and polyethylene terephthalate was used as a polymer for meltblown fibers. Ethylene glycol ester (viscosity ηsp/C=0.42) and nylon 6 (relative viscosity ηrel=2.3), filament web (2.0dtex, 8.3g/m ² ), melt-blown fiber web (fiber diameter respectively PET=2.4μm, 3.4g/m ² , N6=1.6μm, 3.4g/m ² ), through embossing pattern (0.5mm square, crimping area ratio 15%) between embossing roller/flat roller, polyethylene terephthalic acid The net of ethylene glycol ester filaments was partially thermocompressed and welded at 205°C and the web of nylon 6 filaments at 186°C. In addition, it was the same as in Example 8, and the weight per unit area was 20g/ ^m2 respectively. of non-woven fabrics. The performance evaluation results of non-woven fabrics are shown in Table 3 and Table 4.

Compared with various non-woven fabrics before softening treatment, these non-woven fabrics have better softness and good thickness feeling, especially the effect of the polyester non-woven fabric in Example 16 is more remarkable.

These nonwoven fabrics can be used not only for hygienic materials, but also for packaging materials, printing materials, simple clothing, etc., and have a softness that cannot be found in conventional nonwoven fabrics.

(compare columns 8-14)

The non-woven fabrics before the non-bonding concave-convex softening treatment corresponding to Examples 8, 9, 11, 14, 15, 16 and 17 are respectively used as respective comparative examples 8, 9, 10, 11, 12, 13 and 14, Its characteristics are shown in Table 3 and 4.

table 3 Constituent fiber Composition of non-woven fabric F: filament M: meltblown hot pressing embossing Embossed embossed pattern non-woven fabric measuring surface Area ratio of partial heat-welded part Area ratio of concave or convex filament Meltblown Material Fineness (dtex) Material Fineness (μm) above (table) Below (in) Example 8 PP 2.8 PP 1.8 F/M/M/F Diagonal pattern Debossed tortoise shell pattern Low density raised (non-continuous) High Density Raised (Continuous) surface 15 12.5 Example 9 PP 1.2 PP 1.8 F/M/M/F Diagonal pattern Debossed tortoise shell pattern Low density raised (non-continuous) High Density Raised (Continuous) surface 15 12.5 Example 10 PP 2.8 PP 1.8 F/M/M/F Diagonal pattern Raised tortoiseshell pattern Low Density Raised (Continuous) High density bumps (non-continuous) surface 15 25 Example 11 PP 2.8 PP 1.8 F/M/M/F Diagonal pattern Raised tortoiseshell pattern Low Density Raised (Continuous) High density bumps (non-continuous) surface 15 25 Example 12 PP 2.8 PP 1.8 F/M/M/F Diagonal pattern Raised check pattern Low Density Raised (Continuous) High density bumps (non-continuous) surface 15 twenty two Example 13 PP 2.8 PP 1.8 F/M/M/F Diagonal pattern Raised diagonal pattern Low Density Raised (Continuous) High density bumps (non-continuous) surface 15 29 Example 14 RCP 1.8 PP 1.8 F/M/F pin point Debossed tortoise shell pattern Low density raised (non-continuous) High Density Raised (Continuous) surface 15 12.5 Example 15 PP 1.2/2.8 PP 1.8 F/M/M/F Diagonal pattern Debossed tortoise shell pattern Low density raised (non-continuous) High Density Raised (Continuous) surface 15 12.5 Example 16 PET 2.0 PET 2.4 F/M/F braided pattern Debossed tortoise shell pattern Low density raised (non-continuous) High Density Raised (Continuous) surface 15 15 Example 17 N6 2.0 N6 1.6 F/M/F braided pattern Debossed tortoise shell pattern Low density raised (non-continuous) High Density Raised (Continuous) surface 15 15 Comparative Example 8 PP 2.8 PP 1.8 F/M/M/F Diagonal pattern - - Comparative Example 9 PP 1.2 PP 1.8 F/M/M/F Diagonal pattern - - Comparative Example 10 PP 2.8 PP 1.8 F/M/M/F Diagonal pattern - - Comparative Example 11 RCP 1.8 PP 1.8 F/M/F pin point - - Comparative Example 12 PP 1.2/2.8 PP 1.8 F/M/M/F Diagonal pattern - - Comparative Example 13 PET 2.0 PET 2.4 F/M/F braided pattern - - Comparative Example 14 N6 2.0 N6 1.6 F/M/F braided pattern - -

Table 4 Weight per unit area of non-woven fabric (g/m ² ) Thickness of nonwoven fabric under various loads (μm) Bulk rate of non-woven fabric (%) Tensile strength of non-woven fabric (N/3cm width) Stress at 5% stretching of non-woven fabric (N/3cm width) Water pressure resistance of non-woven fabrics (mb) Softness of non-woven fabric mm Softening rate% 1.3g/ ^cm2 10g/ ^cm2 37.5g/ ^cm2 50g/ ^cm2 100g/ ^cm2 vertical horizontal vertical horizontal vertical horizontal Example 8 15 268 189 149 138 119 119 12.2 7.4 5.6 2.1 15 58 42 84 Example 9 15 266 178 140 131 112 115 18.2 7.7 6.1 2.1 15 57 41 76 Example 10 15 266 174 135 129 105 109 13.1 7.5 5.3 1.4 13 58 42 84 Example 11 17 - 184 - - - 115 22.8 7.0 6.8 1.5 16 65 45 75 Example 12 15 241 173 131 130 109 109 13.0 7.7 5.9 1.8 14 59 43 86 Example 13 17 - 185 - - - 116 13.3 7.5 6.1 1.6 16 61 43 88 Example 14 16 - 188 - - - 121 12.0 5.3 4.4 1.3 13 59 40 87 Example 15 15 - 185 - - - 121 16.5 7.2 6.2 1.4 15 59 43 86 Example 16 20 - 162 - - - 157 48.3 18.1 13.3 5.8 - 103 62 76 Example 17 20 - 159 - - - 135 53.0 14.1 8.1 2.4 - 54 35 87 Comparative Example 8 15 224 159 133 124 109 - 14.9 9.1 7.1 2.7 18 69 44 Comparative Example 9 15 220 155 129 119 109 - 19.4 8.3 7.8 2.8 twenty four 75 47 Comparative Example 10 17 - 160 - - - - 19.8 7.8 8.5 1.8 16 87 49 Comparative Example 11 16 - 156 - - - - 12.3 5.6 4.7 1.4 19 68 43 Comparative Example 12 15 - 153 - - - - 17.4 8.0 7.5 2.3 twenty two 69 45 Comparative Example 13 20 - 103 - - - - 53.0 19.0 28.8 11.3 - 135 87 Comparative Example 14 20 - 118 - - - - 55.6 13.6 15.2 4.3 - 62 39

From the results shown in Table 3 and Table 4, it can be found that the objects in the Examples are better than those in the Comparative Examples in terms of bulkiness, tensile strength, stress during elongation, and softness.

The spun-bonded non-woven fabric of the invention has good bulkiness, softness and good strength, and is suitable for non-woven fabrics for hygienic materials. The spunbonded nonwoven fabric of the present invention further contains a hydrophilizing agent mainly in the (B) region, so that it can simultaneously satisfy the four characteristics of bulkiness, softness, water permeability, and rewetting performance as a hygienic material.

Claims (23)

1. spunbond class nonwoven fabric, it is the nonwoven fabric that the net by thermoplastic synthetic fiber's continuous filament yarn constitutes, it is characterized in that: the structure of nonwoven fabric by between the table the inside that connects nonwoven fabric and incorporate part hot pressing welding zone of fiber decorative pattern, and the depression decorative pattern or the protruding pattern that on two faces of nonwoven fabric structure, constitute by the high-density region of non-binding fiber be fixed, be more than 100% by the thickness of the shared nonwoven fabric of the density regions of nonwoven fabric structure and the bulk rate that the ratio of the thickness of the nonwoven fabric of the face of the protruding embossing decorative pattern that contains nonwoven fabric is represented.

2. spunbond class nonwoven fabric according to claim 1 is characterized in that the high-density region of non-binding fiber disposes continuously.

3. spunbond class nonwoven fabric according to claim 1 and 2 is characterized in that, the discontinuous dispersion of the high-density region of non-binding fiber exists.

4. according to any described spunbond class nonwoven fabric of claim 1-3, it is characterized in that bulk rate is 105-400%.

5. according to any described spunbond class nonwoven fabric of claim 1-4, it is characterized in that the area occupation ratio of part hot pressing welding zone of fiber decorative pattern is 5-40%, the area occupation ratio of the depression of the high-density region of non-binding fiber or protruding pattern portion is 5-40%.

6. spunbond class nonwoven fabric, form by composite web, this composite web is by one deck thermoplastic synthetic fiber continuous filament yarn net at least and one deck meltblown fiber web layer is long-pending at least forms, this nonwoven fabric is characterised in that, the structure of nonwoven fabric is incorporate part hot pressing welding zone of fiber decorative pattern by the table the inside that connects nonwoven fabric, and the depression embossing that on two faces of nonwoven fabric structure, constitutes by the high-density region of non-binding fiber or protruding pattern and be fixed, be more than 100% by the thickness of the shared nonwoven fabric of the density regions of nonwoven fabric structure and the bulk rate that the ratio of the thickness of the nonwoven fabric of the face of the protruding embossing decorative pattern that contains nonwoven fabric is represented.

7. spunbond class nonwoven fabric according to claim 6 is characterized in that the high-density region of non-binding fiber disposes continuously.

8. according to claim 6 or 7 described spunbond class nonwoven fabric, it is characterized in that the discontinuous dispersion of the high-density region of non-binding fiber exists.

9. according to any described spunbond class nonwoven fabric of claim 6-8, it is characterized in that bulk rate is 105-400%.

10. according to any described spunbond class nonwoven fabric of claim 6-9, it is characterized in that the area occupation ratio of part hot pressing welding zone of fiber decorative pattern is 5-40%, the depression decorative pattern of the high-density region of non-binding fiber or the area occupation ratio of protruding pattern portion are 5-40%.

11. spunbond class nonwoven fabric hygienic material, it is the nonwoven fabric that the net by thermoplastic synthetic fiber's continuous filament yarn constitutes, it is characterized in that: the structure of nonwoven fabric is incorporate part hot pressing welding zone of fiber decorative pattern by the table the inside that connects nonwoven fabric, and the depression decorative pattern that on two faces of nonwoven fabric structure, constitutes or protruding pattern and be fixed by the high-density region of non-binding fiber, the bulk rate of being represented by the thickness of the shared nonwoven fabric of the density regions of nonwoven fabric structure and the ratio of the thickness of the nonwoven fabric of the face of the protruding embossing decorative pattern that contains nonwoven fabric is more than 100%, and has applied hydrophilic agent.

12. hygienic material according to claim 11 is characterized in that with spunbond class nonwoven fabric hydrophilic agent mainly is included in the high-density region of non-binding fiber.

13., it is characterized in that bulk rate is 105-400% according to claim 11 or 12 described spunbond class nonwoven fabric.

14. according to any described spunbond class nonwoven fabric of claim 11-13, it is characterized in that the area occupation ratio of part hot pressing welding zone of fiber decorative pattern is 5-40%, the decorative pattern recess of the high-density region of above-mentioned non-binding fiber or the area occupation ratio of protuberance are 5-40%.

15., it is characterized in that spunbond class nonwoven fabric hygienic material has been applied in hydrophilic agent according to any described spunbond class nonwoven fabric of claim 11-14 after implementing corona discharge.

16. spunbond class nonwoven fabric hygienic material, form by composite web, this composite web is by one deck thermoplastic synthetic fiber continuous filament yarn net at least and one deck meltblown fiber web layer is long-pending at least forms, it is characterized in that, the structure of nonwoven fabric is by the part hot pressing welding zone of fiber decorative pattern inside the table that connects nonwoven fabric, and the depression embossing that on two faces of nonwoven fabric structure, constitutes by the high-density region of non-binding fiber or protruding pattern and be fixed, be more than 100% by the thickness of the shared nonwoven fabric of the density regions of nonwoven fabric structure and the bulk rate that the ratio of the thickness of the nonwoven fabric of the face of the protruding embossing decorative pattern that contains nonwoven fabric is represented.

17. spunbond class nonwoven fabric hygienic material according to claim 16 is characterized in that hydrophilic agent mainly is included in the high-density region of non-binding fiber.

18. require 16 or 17 described spunbond class nonwoven fabric hygienic materials according to claim, it is characterized in that bulk rate is 105-400%.

19. according to any described spunbond class nonwoven fabric hygienic material of claim 16-18, it is characterized in that, the area occupation ratio of part hot pressing welding zone of fiber decorative pattern is 5-40%, and the decorative pattern recess of the high-density region of non-binding fiber or the area occupation ratio of protuberance are 5-40%.

20., it is characterized in that in spunbond class nonwoven fabric hygienic material, nonwoven fabric has been applied in hydrophilic agent after implementing Corona discharge Treatment according to any described spunbond class nonwoven fabric hygienic material of claim 16-19.

21. spunbond class nonwoven fabric disposable hygienic material, it is characterized in that, in any described spunbond class nonwoven fabric hygienic material of claim 11-20, the face with the depression of high-density region of non-binding fiber of this nonwoven fabric or protruding pattern is used for the surface on top layer.

22. a disposable hygienic material is characterized in that, in any described spunbond class nonwoven fabric hygienic material of claim 11-20, the face with the depression of high-density region of non-binding fiber of this nonwoven fabric or protruding pattern uses as the reverse side on top layer.

23. a disposable hygienic material is characterized in that, any described spunbond class nonwoven fabric of claim 6-10 is used for standing gather portion and/or backing layer.

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