JPH1181151A - Elastic nonwoven fabric - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the production of an elastic nonwoven fabric controlled in elasticity in a prescribed extent without changing a basic fiber tissue by printing a resin in a prescribed pattern on a nonwoven fabric comprising a polyurethane elastomer filaments. SOLUTION: This elastic nonwoven fabric reduced in the elasticity of printed portions is obtained by accumulating melt-blown polyurethane elastomer filaments on a net conveyer substantially without bundling the filaments, nipping the accumulated filaments with heated rollers or the like to thermally integrally fuse the laminated polyurethane elastomer filaments to each other at their contact points, and subsequently printing the formed highly elastic nonwoven fabric having a breaking elongation of >=200% and a 100% elongation recovery of >=85% with a resin for controlling the elasticity in at least one pattern selected from stripes such as vertical stripes, lateral stripes, right upward slant stripes and left upward slant stripes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-woven fabric having high elasticity (elongation at break and 100% elongation recovery), and more particularly, to apply the resin to the surface of the non-woven fabric to improve the elasticity. The present invention relates to a structure of a nonwoven fabric reduced to a predetermined value.

[0002]

2. Description of the Related Art Conventionally, various nonwoven fabrics have been proposed and used in many fields. However, most of these nonwoven fabrics are nonwoven fabrics composed of inelastic polymers such as polyamide, polyester and polyolefin. The practical use of nonwoven fabrics formed of fibers having high elasticity such as polyurethane elastic bodies is merely disclosed in Japanese Patent Publication No. 64-8746 or Japanese Patent Publication No. 1-30945.

A nonwoven fabric of polyurethane fiber having high elasticity obtained by such a method, particularly a spunbond obtained by laminating melt-spun polyurethane elastic filaments by self-fusion, has high elongation, high recovery rate, and flexibility. It has many excellent characteristics such as water permeability, air permeability and dust collecting property, and is widely used for various uses such as "disposable diapers" disclosed in Japanese Utility Model Publication No. 4-22733.

[0004]

However, such a non-woven fabric having high elasticity, such as a non-woven fabric made of polyurethane elastic filaments having a breaking elongation of 200% or more and a 100% elongation recovery of 85% or more, has been proposed. In addition, when this and another fiber material are overlapped and adhered to each other, if a tensile force for separating the two is applied, there is a problem that the shape-retaining state easily collapses due to aging.

[0005] The above-mentioned problems of the highly stretchable nonwoven fabric will be specifically described with reference to the disposable diaper described in Japanese Utility Model Publication No. Hei 4-22733. In Fig. 5, reference numeral 1 denotes a disposable diaper; Part
A top sheet 3 having high water permeability, a back sheet 4 having waterproof properties, an absorbent material 5 interposed between the two sheets 3 and 4, and an elastic body 6 which expands and contracts in the longitudinal direction of the diaper and tightens the base of the wearer. And a side flap 7.

Reference numeral 8 denotes an ear edge serving as a core of the disposable diaper, which is provided at both ends of a rear waist portion of the diaper, and is a nonwoven fabric having high elasticity and excellent flexibility which is an object of the present invention. Is made of a non-woven fabric of polyurethane elastic filaments. Reference numerals 9 denote pressure-sensitive adhesive tapes fixed to the free ends of the ear sides 8, respectively, for connecting a front waist portion of the disposable diaper.

[0007] The disposable diaper 1 is formed by folding the main body portion 2 in the vertical direction, and then bonding the right or left pressure-sensitive adhesive tape 9 to the other side 8 under pressure to form a pants type. A side 8 made of a nonwoven fabric having elasticity and flexibility at portions corresponding to the left and right waist portions of the disposable diaper
Diaper is significantly superior to the conventional type in the width direction of the diaper, and has an excellent fit around the waist, almost completely excreting excrement from the back. Has the effect of blocking.

However, when such a disposable diaper 1 is worn for a long time, the pressure-sensitive adhesive tape 9 may be changed over time.
The shape-retaining state of the ear 8 and the ear side 8 is broken, and the fit is often deteriorated, causing the above-mentioned problem.

Such a phenomenon is caused by the fact that each filament of the polyurethane elastic filament group constituting the nonwoven fabric of the ear side 8 is fixed at the initial position at the initial stage of the adhesion between the pressure-sensitive adhesive tape 9 and the ear side 8. On the other hand, the position of each filament is displaced due to aging and the arrangement state is broken, and the bonding target surface of the ear side 8 is formed by the uneven surface of a large number of filaments. Slightly poor adhesion. It is thought that the above two requirements appear together.

In order to solve the problem of lack of morphological stability generated on the nonwoven fabric of the ear edge 8, even in a conventional diaper shape, a different side of the nonwoven fabric forming the ear edge 8 from the nonwoven fabric. Attempts have been made to sew the fiber material of the structure and form a new adhesive surface for stopping the pressure-sensitive adhesive tape 9, but such improvement complicates the diaper structure and complicates the manufacturing process. And there is a disadvantage that the cost is increased.

[0011] The present invention is intended to solve the above-mentioned problems that occur when a highly stretchable nonwoven fabric is used as a member in a department requiring shape stability. The resin is partially printed on the nonwoven fabric to partially reduce the stretchability of the nonwoven fabric, thereby preventing deformation inside the nonwoven fabric.

[0012]

In order to achieve the above object, the present invention has the following arrangement. That is, the first of the present invention
According to the invention, a vertical stripe, a horizontal stripe, and an upper right inclined stripe are formed on a nonwoven fabric having a breaking elongation of 200% or more and a 100% elongation recovery rate of 85% or more by using the resin for suppressing the elasticity. ,
A stretchable nonwoven fabric characterized by printing at least one stripe pattern selected from a stripe pattern group such as a left-up slope stripe pattern and reducing the stretchability of the printed portion.

In a second aspect of the present invention, the structure of the nonwoven fabric itself is specified in the stretchable nonwoven fabric according to the first aspect, wherein a melt-spun polyurethane elastic filament is substantially bundled as the nonwoven fabric. Stacked without
The nonwoven fabric made of polyurethane elastic fiber is used in which the contact points of the laminated filaments are joined by the filaments themselves.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described. In the following description, the same components as those of the related art are denoted by the same reference numerals, and detailed description thereof will be omitted. First, the configuration of the nonwoven fabric as the base fabric will be described.

The nonwoven fabric used in the present invention has a breaking elongation of 20.
It has a physical property of 0% or more, and a recovery rate at 100% elongation of 85% or more. In the present embodiment, a polyurethane elastic fiber non-woven fabric applied by one of the applicants in Japanese Patent Publication No. 1-30945 is used. As the polyurethane elastic body constituting the nonwoven fabric, a known thermoplastic polyurethane elastic body which can be melt-spun is applied. Such a polyurethane elastic body usually comprises a low melting point polyol having a molecular weight of 500 to 6,000, an organic diisocyanate having a molecular weight of 500 or less, and a chain extender having a molecular weight of 500 or less.

As described above, the polyurethane elastic body of this embodiment is synthesized from a polyol, an organic diisocyanate, and a chain extender, and is preferably used when the polyol component contains 65% by weight or more of the entirety. And particularly preferred is 68% by weight or more. When the content of the polyol component is small, the elongation and elongation recovery of the obtained nonwoven fabric are low.

The nonwoven fabric of this embodiment is formed by laminating and laminating polyurethane elastic filaments without bonding over substantially the entire length of the yarn, and the average diameter of the monofilament is usually 30 μm or less. , Preferably on average less than 25 microns, particularly preferably less than 20 microns.

The cross-sectional shape of the polyurethane elastic filament constituting the nonwoven fabric of the present embodiment can take various shapes such as a circular shape, an irregular shape, and a hollow body. From the viewpoint of sheet formability and elasticity at the time of formation, those having a circular cross section are preferable.

The nonwoven fabric is formed by laminating such polyurethane elastic filaments, and the points of contact between the fibers constituting the laminate are joined by the fibers themselves.
Such a bonded state is achieved by fusing the polyurethane elastic fibers to each other by heat.

In the present invention, a striped pattern is printed on a nonwoven fabric having such a structure by using a resin for suppressing the elasticity of the nonwoven fabric. As the resin agent, dextrin, sodium alginate, carboxymethyl cellulose,
Water-soluble resins such as gum arabic, or non-water-soluble resins such as emulsion-type acrylic resins, vinyl resins, and urethane resins. In the present embodiment using polyurethane elastic filaments as the nonwoven fabric constituent fibers, crosslinkable polyurethane or latex is preferred.

The pattern of the surface of the nonwoven fabric formed by the resin material is as follows: vertical stripes shown in FIG. 2a, horizontal stripes shown in FIG. 2b, inclined stripes on the upper right shown in FIG. At least one of stripe patterns, such as an upwardly inclined slope stripe, is selected. In addition, you may print two striped patterns simultaneously. As one of such composite shapes, there is an oblique lattice pattern obtained by combining an upper right inclined stripe and an upper left inclined stripe.

In the present invention, the elasticity of the printed resin region is naturally lower than that of the non-resin region. Therefore, what kind of figure is adopted in the striped pattern is determined by the direction on the nonwoven fabric that needs to be controlled in elasticity and the area of the area. Further, in each pattern shown in FIG. 2, the width of the resin layer 10 on which the resin material is imprinted and the width of the non-resin layer 11 composed of only the base cloth are the same, but different widths such as a combination of a narrow width and a wide width. It may be a combination of the width dimensions. In addition, the direction shown by T in FIG. 2 shows the nonwoven fabric winding and winding directions in the manufacturing process.

In the present embodiment, the elongation at break of the nonwoven fabric forming the base fabric is usually 200% or more, preferably 300%.
Although the breaking strength is different depending on the thickness of the nonwoven fabric, it is usually 0.2 kg / weight per 100 g / cm ^2.
cm or more, preferably 0.5 kg / cm or more. The recovery rate at 100% elongation is usually 85% or more, preferably 90% or more.

The resin layer 10 has the following physical properties as compared with the non-resin layer 11, that is, the physical properties of the base cloth. That is, in a nonwoven fabric of the same configuration impregnated with a resin agent and having a thickness of about の of a cloth, the elongation at break is in the range of 30 to 200%, and the breaking strength varies depending on the thickness of the nonwoven fabric. It is in the range of 0.4 to 1.5 kg / cm per 100 g / cm ² .

The resin layer 10 having the above-mentioned physical properties is printed by a known one-sided one-color printing machine shown in FIGS. In FIG. 3, 12 is a pressure cylinder, 13 is a printing roll,
14 is a mandrel, 15 is a gluing roll, 16 is a gluing box for storing the resin agent, 17 is a doctor, 18 is a ring doctor, 19 is wrapping, 20 is a stretchable nonwoven fabric targeted by the present invention, 21 is under The cloth 22 is a blanket.

In such an apparatus, the nonwoven fabric 20 rotates together with the undercloth 21 and the blanket 22 in the direction of the arrow in FIG. On the other hand, the resin material in the glue box 16 is transferred to the printing roll 13 via the rotating glue roll 15, and the resin material is attached to the convex portion formed on the roll surface. At the same time, this is printed on the nonwoven fabric 20. FIG. 4 shows an example of the printing roll 13 in which the width of the convex portion 23 formed on the peripheral surface is slightly widened and the width of the concave portion 24 is narrowed accordingly. Continuous printing of the inclined stripe pattern.

The nonwoven fabric 21 of the present embodiment is formed by such a printing process. The physical properties of the resin layer 10 after printing depend on the physical properties of the base fabric itself and the number of filaments constituting the base fabric. Of the performance of the resin agent that causes the base material to adhere to each other, and the factors of the degree of impregnation of the base material with the resin agent. The physical properties of the entire nonwoven fabric composed of the combination of the resin layer 10 and the non-resin layer 11 indicate values in a range between the two layers 10 and 11.

As described above, the nonwoven cloth according to the present invention is obtained by printing a striped pattern on a base cloth having a high breaking elongation and a 100% elongation recovery rate by using a resin agent that suppresses its elasticity.
As a result, the breaking elongation and the 100% elongation recovery rate are reduced to predetermined values. As a result, collapse of the laminate caused by the movement of the constituent filaments in the nonwoven fabric and reduction in the adhesiveness of the surface are prevented. You do it.

An embodiment of the present invention will be described below with reference to FIG. In the following examples, as in the above description,
The same components as those in the related art are denoted by the same reference numerals, and detailed description thereof will be omitted. In the above description and the description of the following examples, the elongation at break was measured in accordance with JIS.
L1096-1990, and the 100% elongation recovery rate is based on JIS L 1096-1.
990.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The non-woven cloth used in this embodiment is Japanese Patent Publication No. 1-309.
No. 45, obtained by the method described in Example 1 and passing through the following process. That is, 5548 parts of dehydrated polytetramethylene glycol having a hydroxyl value of 102 (the following parts all mean parts by weight) and 1.4-bis (β
-Hydroxyethoxy) benzene (499 parts) was charged into a kneader equipped with a jacket, sufficiently dissolved with stirring, and maintained at a temperature of 85 ° C., and 1953 parts of P, P′-diphenylmethane diisocyanate was added thereto and reacted. Was. When the stirring is continued, a powdery polyurethane is obtained in about 30 minutes. The polyurethane is formed into pellets by an extruder, and the concentration of the polyurethane measured at 25 ° C. in dimethylformamide is 1 g / 100 c.
A polyurethane elastomer having a relative viscosity of 2.50 was obtained.
Using the polyurethane elastomer pellets obtained in this manner as a raw material, a melt blow spinning apparatus having slits for injection of heated gas on both sides of 0.8 mm diameter nozzles arranged in a row was used, and the melting temperature was 245 ° C. The polymer was discharged at a rate of 0.5 g / min, and air heated to 200 ° C. was jetted from the slit at a pressure of 3.5 kg / cm ² to be thinned. The thinned filaments were collected on a conveyor made of a 30-mesh wire net placed 25 cm below the nozzle, and were sandwiched between rollers to obtain a nonwoven fabric. In this nonwoven fabric, monofilaments of polyurethane elastic fibers were spread and laminated, and the entanglement points between the filaments were joined to each other by fusion. The physical properties of this nonwoven fabric were as follows. Weight 90g / cm ² Tensile strength 1.1kg / cm Elongation at break 550% 100% Elongation recovery 92% Bending degree 35mm Filament diameter 20 microns

The printing process shown in FIG.
The pattern shown in FIG. 2A was printed by a printing machine including a step of drying the nonwoven fabric after printing. NIPOL LX (trade name, manufactured by Zeon Corporation) is used as the resin agent for printing.
An 854 series acrylate latex was used.
The resin agent has the following contents. That is, the total solid content in the resin agent was 45%, the pH was 6.5, and the viscosity was 20 mpa.
s, the surface tension was 27 mN / m, the specific gravity was 1.04, and the average particle size was 0.20 μm, and it could be used directly as a printing liquid as it was.

[0032] The nonwoven fabric (basis weight 90 g / m ²⁾ as the fabric, i.e. a non-resin layer 11, the fabric was printed with the latex to the nonwoven fabric on one side thereof, i.e. the resin layer 10 (basis weight 119.2 g / m ²⁾ , Respectively, according to JIS 1096-1
According to 990, the tear strength was measured. Table 1 shows the results.

[0033]

[Table 1]

A nonwoven fabric in which the resin layer 10 and the non-resin layer 11 are printed in a striped manner, as shown in FIG.
No. 733 discloses a disposable diaper, which was used as an edge 8 of the disposable diaper. Table 2 shows the test results.

[0035]

[Table 2]

In the measurement items shown in Tables 1 and 2, the tear strength, breaking strength and elongation at break were all JIS 109
6-1990, the contents shown in each column of 200% extension (after leaving for 1 hour), 300% extension (after leaving for 1 hour), and 300% extension (after leaving for 60 hours) are as follows. The change in the state of attachment is shown when the number of attachment points between the pressure-sensitive adhesive tape 9 and the ear side 8 is set to 10 at five test objects.

As can be seen from Table 2, the product number A having the largest latex-coated surface is 200 times more than B and C.
The remaining number of pieces in the fastening state at the time of% extension and at the time of 300% extension are both dramatically increased, which clearly shows that the fastening is strong.

[0038]

As described above, the nonwoven fabric according to the present invention comprises:
Elongation at break is 200% or more, 100% elongation recovery rate is 85%
In the highly stretchable nonwoven fabric as described above, the nonwoven fabric in the required area is reduced in its elasticity to a predetermined degree by a simple means of printing a striped pattern with a resin on the surface without changing the basic fiber composition. This has the effect of dramatically improving the collapse of the arrangement state of each filament due to the temporal change described at the beginning or the roughening of the surface flatness possessed by such a nonwoven fabric. From this effect, the field of use of the non-woven fabric having high elasticity is widened, and the elasticity of the non-woven fabric can be adjusted freely to meet various requirements.

[Brief description of the drawings]

FIG. 1 is a plan view showing a usage example of the nonwoven fabric of the present invention.

FIG. 2 is a plan view showing each example of a striped pattern.

FIG. 3 is an explanatory view showing a longitudinal section of the printing machine.

FIG. 4 is a perspective view showing a printing roll of the printing machine.

FIG. 5 is a plan view showing a usage example of a conventional nonwoven fabric.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Disposable diaper 2 Main part 8 Ear side 9 Pressure sensitive adhesive tape 10 Resin layer 11 Non-resin layer 13 Printing roll 16 Glue box 20 Nonwoven fabric 23 Convex part 24 Concave part

Claims (2)

[Claims] 1. A non-woven fabric having a breaking elongation of 200% or more and a 100% elongation recovery rate of 85% or more, a vertical stripe, a horizontal stripe, and a right-upward slope formed by the resin that suppresses the elasticity. A stretchable nonwoven fabric characterized by printing at least one stripe pattern selected from a group of stripe patterns, such as stripes and upwardly sloped stripes, and reducing the stretchability of the printed portion. 2. A non-woven fabric comprising polyurethane elastic fibers, wherein melt-spun polyurethane elastic filaments are laminated without being substantially bundled, and contact points of the laminated filaments are joined by the filaments themselves. The stretchable nonwoven fabric according to claim 1, wherein the stretchable nonwoven fabric is used.