JPH09300513A - Nonwoven composite - Google Patents

Abstract

(57) Abstract: A spunbonded non-woven fabric using polypropylene filaments having high tensile strength and tear strength has drawbacks of water pressure resistance, water absorption and hygroscopicity, which are laminated and bonded with another non-woven fabric. By doing things,
Selectively improve depending on the application. SOLUTION: A synthetic organic fiber, wood pulp,
A nonwoven fabric composite comprising a spunlaced nonwoven fabric using rayon, cotton or a mixed fiber thereof and / or a layer of a nonwoven fabric formed by flash spinning using polyolefin.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a laminate of polypropylene spunbonded nonwoven fabric and another substrate, and is excellent in good balance in tensile strength, tear strength, water pressure resistance, water absorption, flexibility and moisture permeability. Non-woven composites.

[0002]

2. Description of the Related Art A non-woven fabric, which is a cloth-like material in which sheet-like aggregates of fibers are joined, has different functions depending on the fiber type or manufacturing method. (Short) fibers that are often used in nonwoven fabrics include synthetic fibers and recycled fibers such as rayon, polyester, polypropylene, nylon, vinylon, acrylic, and aramid fibers. Next, when classifying non-woven fabric manufacturing methods, there are dry type, wet type, spun bond, as well as dry type pulp, melt blow, flash spinning, burst fiber, Meu opening, split filter and the like. In addition, the relationship between the fiber length and the manufacturing method is as follows: a wet method using pulp having a fiber length of mm order, dry paper, a dry method using staple (short fibers) having a fiber length of cm order, spunlace, It is a spunbond that uses filaments (long fibers) with a fiber length of ∞ order.

Generally, the structure and properties of a non-woven fabric are determined by complicatedly intertwining factors such as the fibers used, the method of forming the web, and the method of adhering the web. Spunlace nonwoven fabric using short polyester fibers (eg, Sontara <registered trademark> manufactured by DuPont, USA) entangles fibers by a high-pressure water stream and mechanically bonds them together, thereby providing flexible and drapable properties. Is known (Japanese Patent Publication No. 3-736)
No. 65). Spunbonded non-woven fabric using polypropylene filament, which is very different from non-woven fabric using short fibers (for example, Typer <registered trademark> manufactured by DuPont, USA)
Since it is directly connected by spinning and is mainly bonded by self-adhesion, it has the same strength in any direction of the non-woven fabric, exhibits excellent durability against impact, hooking, tearing, etc., and has no frayed edges. It is also resistant to decay, mold, moisture, pests, etc. and is stable to chemicals. Furthermore, it has a wide temperature range that can be used, and because it does not generate harmful gas during combustion, it has excellent recyclability and does not expand or contract due to moisture,
It is known to have the characteristic of being lightweight (Japanese Patent Publication No. 55-42175). In addition to the spunbond method, there are flash-spun nonwoven fabrics as the directly spun nonwoven fabrics. This flash-spun nonwoven fabric (for example, Tyvek <registered trademark> manufactured by DuPont, USA) is subjected to phase separation using a polymer solution of a fiber-forming polymer polyolefin and a solvent (under high temperature and high pressure), and then in a low temperature and low pressure region. By discharging, the solvent rapidly gasifies and expands, the polymer solidifies while being stretched, and because it is a network-like continuous fiber composed of extra fine fiber elements that has a unique structure, it is high strength and toughness. Has a high degree of water pressure resistance and moisture permeability,
It has breathability, opacity and surface smoothness (Japanese Patent Publication Nos. 40-28125, 41-6215, 42-19520, and 43-21112).
issue).

Also known is a multi-layered structured fabric using a combination of two or more types of non-woven fabrics, which is to obtain the composite physical properties by combining the unique properties of each non-woven fabric according to the application. Further, there are a combination of a film and a non-woven fabric, a combination of a low density polyethylene foam sheet and a non-woven fabric instead of the film, or a composite having a three-layer structure using these. This composite is a laminated product in which a non-woven fabric layer serving as a base material and a thin layer covering the same are planarly bonded, and a composite product in which a mating layer to be composited with the non-woven fabric base material is unevenly bonded. May be distinguished.

[0005]

For example, in the case of a spunlace nonwoven fabric using polyester short fibers, there is a drawback in that the tensile strength and tear strength are small and the water pressure resistance is small at the same time due to the fiber length used and the bonding. It has the advantages of having excellent water absorption, flexibility and moisture permeability.

In the case of a spunbonded nonwoven fabric using polypropylene filaments, spun yarns are individually and independently deposited in a random loop shape to form a web, so that the tensile strength and tear strength are large and the air permeability is also high. It has the advantage of being large, but has the drawback of being relatively poor in water pressure resistance, water absorption and flexibility. Next, in the case of a flash-spun non-woven fabric using a polyolefin, there are advantages that it has good tensile strength, tear strength, and excellent water pressure resistance and moisture permeability, and that it is relatively inferior in water absorption and flexibility. .

An object of the present invention is to combine a spunbonded non-woven fabric using polypropylene filaments with at least one of a spunlaced non-woven fabric and a flash spun non-woven fabric, and selectively select tensile strength, tear strength, water resistance and water absorption depending on the application. The object of the present invention is to provide a composite having improved properties and moisture permeability in a well-balanced manner, and particularly to provide a composite particularly suitable for various wiper applications or surgical litter applications.

[0008]

According to the present invention, a spunbonded non-woven fabric layer made of polypropylene filament is laminated with a spunlaced non-woven fabric layer made of polyester fiber and / or a non-woven fabric layer made by flash spinning of polyolefin. And a nonwoven fabric composite.

Conventional spunbonded nonwoven fabrics can be used as the spunbonded nonwoven fabric using filaments such as polypropylene, nylon, polyester and polyethylene used in the present invention. For example, Japanese Examined Japanese Patent Publication Sho 55-4
No. 2175, the filaments melt-spun from the spinning nozzle are subjected to friction charging, forced charging,
Disperse evenly by either or a combination of the collision diffusion method and the airflow diffusion method, and randomly deposit and collect on a net conveyor or drum net to form a web (thin sheet). The bonding is performed by using an adhesive, the low melting point polymer is simultaneously spun and mixed, or the irregular mesh plate-like binder is sprinkled during the web formation for melt bonding. Preferred polymers include polypropylene fibers.

Spunlace nonwoven fabric is, for example, Japanese Patent Publication No. 3-
It is described in Example 2 of Japanese Patent Publication No. 73665, and 2.2c
A polyester staple fiber having a fiber length of m was formed into a web by an air flow collecting method of the method described in US Pat. No. 3,977,074 to Zafigrough, and the web was placed on a fine mesh and covered with Hermack paper. Is formed and then passed under the jet bank to form. As the short fibers constituting the spunlaced nonwoven fabric sheet, synthetic organic fibers, wood pulp, rayon, cotton, or mixed fibers thereof can be used.

Nonwoven fabrics having a reticulated structure of plexifilamentary film of fibrils and fibrils of polyolefin by flash-spinning are also known.
The manufacturing method is a method in which a bat formed by accumulating filaments of polyolefin such as polyethylene while intersecting by a flash spinning method is passed through a nip and compressed. According to the flash spinning method, a solution of a polymer dissolved in a low boiling point solvent is extruded from a spinning nozzle and the solvent is instantly vaporized. The resulting filaments can be sprinkled during web formation to produce a non-woven fabric that is densely bonded at multiple fusing points. The non-woven fabric produced by the flash spinning method has a higher density and is more durable than other non-woven fabrics, for example, a melt blown method using a heating fluid jet or a spunbond method using a compressed air flow. Excellent in properties such as water resistance, opacity, breathability and moisture permeability. As the synthetic resin constituting the non-woven fabric sheet, polyolefin, particularly high density polyethylene is preferable, but polypropylene or a copolymer of polyolefin or a copolymer with polyolefin such as polyester can also be used.

As the spunbonded nonwoven fabric which can be used in the present invention, TYPER <registered trademark> commercially available from DuPont, USA can be used. A type of spunbonded nonwoven fabric manufactured by DuPont, USA <Registered trademark>
Table 1 shows the typical characteristics of the.

[0013]

[Table 1]

As the spunlace nonwoven fabric that can be used in the present invention, Sontara <registered trademark> commercially available from DuPont, USA can be used. As described above, this spunlaced nonwoven fabric is a thin column of water from an orifice bank having a diameter of, for example, 0.05 to 0.13 mm while supporting an aggregate composed of wood pulp and synthetic organic fibers with fine gold steel or the like. Jet processing, jet energy E
It can be manufactured by supplying E · I, which is the product of the impact force I of the jet flow.

The spunlaced nonwoven fabric obtained by the above-mentioned manufacturing method has a very high barrier property because millions of wood pulp fibers and synthetic organic fibers arranged in random directions are intertwined with each other. Among these spunlaced nonwoven fabrics, a mixture of wood pulp fiber and polyester fiber is preferable as it is inexpensive and satisfies the requirements such as water absorption. A suitable wood pulp / polyester mixing ratio is 80
-20% / 20-80%. The weight per unit area of the spunlaced nonwoven fabric made of wood pulp / polyester is in the range of 30 to 100 g / m ² , although it depends on the mixing ratio of the both. The spunlace nonwoven fabric made of wood pulp fibers and polyester fibers has a gripping breaking strength of approximately 10.4 to 22.6 kg, depending on the entanglement of the fibers. The Frazier air permeability is 250-8.
It has a breathability of 00 cm ³ / cm ³ · sec, is soft and supple.

A non-woven sheet having a network structure of a polyolefin plexifilamentary film-fibril strand by flash spinning has a weight of 40.
In the range of to 150 g / m ^2, water pressure resistance 500-3
000mmH ₂ O, preferably in the range of 800~3000mmH ₂ O, moisture permeability (according to JIS-Z-0280 modified method) is not less 3000g / m ^2/24 hours or more, air permeability (Gurley air permeability) is 10 A material within the range of 100 seconds is suitable. As a material satisfying all the above-mentioned various properties required for this non-woven fabric sheet, for example, Tyvek <registered trademark>, which is a high-density polyethylene non-woven fabric manufactured by DuPont, USA, can be mentioned. This Tyvek <registered trademark>
Is a nonwoven fabric obtained by spinning high-density polyethylene by the above-mentioned flash spinning method and thermocompression-bonding this to heat-bond the filaments. This non-woven fabric is a functional material that is lightweight, has excellent tear strength, and has excellent water pressure resistance, moisture permeability, and air permeability. There are various types of Tyvek <registered trademark>, but in the present invention, the types of Tyvek <registered trademark># 10 and # 14 are suitable, and they are softer and more flexible than Tyvek <registered trademark># 10. Tyvek <registered trademark># 14 having properties is more preferable. Tables 2 and 3 show the typical characteristics.

[0017]

[Table 2]

[0018]

[Table 3]

The non-woven fabric composite obtained by laminating and joining at least two non-woven fabrics of the present invention can be manufactured by a standard method in the non-woven fabric industry. General methods include sewing, dot bonding, full surface bonding, ultrasonic bonding, heat fusion and the like. At least two layers of non-woven fabric constituting the non-woven fabric composite of the present invention are laminated and joined by a method appropriately selected from these general methods depending on the application of the non-woven fabric composite of the present invention.

[0020] Particularly when the bonding using a practical binder is adopted, these non-woven fabrics can be bonded by a combination of resinous binders, and the non-woven fabric may be bonded depending on the difference in the adhesiveness between two or more binders used. It enables bonding with the required distribution of bonding strength while maintaining a good average bonding strength. The required distribution of the adhesive strength can also be obtained by changing the size of the adhesive spot in a sufficiently wide range using a single resin binder giving a specified average adhesive strength. The adhesion concentration can be controlled by the amount of the binder substance used. The binder may be applied by any method known in the art. This includes methods of applying as a dispersion or solution or as a binder film as a particulate or powdered material. If desired, these binders can be activated by heating by a known method.

[Embodiment of the Invention] An embodiment of the present invention will be described below. One embodiment of the nonwoven fabric composite according to the present invention is a spunbonded nonwoven fabric type Spunbonded nonwoven fabric type 3207 <registered trademark> (basis weight 68 g / m ² ) manufactured by DuPont and a commercially available spunlaced nonwoven fabric manufactured by DuPont. Spunlace Nonwoven Sontara K
-835 <registered trademark> (grammage 78 g / m ² ) is dot-bonded using a hot melt adhesive whose main component is an ethylene / EVA copolymer resin. Sontara K-835 <registered trademark>
Is a non-porous wood pulp-polyester spunlace non-woven fabric, which has two surfaces, a wood pulp fiber layer and a polyester fiber layer. Therefore, a molten hot melt adhesive is applied to the polyester side by spraying with a nozzle diameter of 3 mm. To do. The hot melt adhesive is 200 ° C to 250 in advance.
Use the one melted at a temperature of ° C. The final coating amount of the hot melt adhesive is adjusted to about 30 to 50 g / m ² . Next, one side of Typer <registered trademark> and Sontara <
Laminate with the polyester side coated with the registered trademark> adhesive.

The following embodiment is different from the first embodiment in the bonding method. This another embodiment (second embodiment)
In the above method, the spunbonded nonwoven fabric and the spunlaced nonwoven fabric are laminated and adhered by a generally well-known extrusion lamination method instead of hot melt adhesion. The spunbond non-woven fabric and the spun lace non-woven fabric used were TYPE 3207 <registered trademark> as in Example 1.
And Sontara K-835 <registered trademark>, and these are laminated by lamination using a thermoplastic resin such as polyethylene melted by heating.

A low-density polyethylene resin heated and melted at a temperature of 250 ° C. to 300 ° C. is fed from a T-die at a delivery speed of 100 to 150 m / sec on average from a unwinding roll TYPER 3207 <registered trademark> or Extruded on the side of wood pulp of Sontara K-835 (registered trademark),
By simultaneously supplying Sontara K-835 <registered trademark> or Typer 3207 <registered trademark> from different directions,
Typer 3207 <registered trademark> and Sontara K-835 <registered trademark> are bonded together by using the extruded resin as an adhesive. The laminated Typer <-> Sontara <-> composite passed through a chill roll,
It is wound up by the winding section. The extruded resin is Type 320
7 Either side of <registered trademark> or Sontara K-835 <
About 20 to 30μ in the bonded part with the registered trademark> wood pulp layer
Form a layer of adhesive with a thickness of m.

Table 4 shows the results of the comparison of the properties of the non-woven composite according to the invention according to the first and second embodiments with the DuPont spunbonded non-woven type 3207 <registered trademark>. As shown in Table 4, the non-woven fabric composite according to the present invention has excellent composite properties in tensile strength, tear strength and water resistance as compared with the conventional single non-woven fabric, and at the same time, it has a span. The excellent water absorbency and moisture permeability of the lace nonwoven fabric are maintained.

Therefore, among the non-woven fabric composites in which the spunbonded non-woven fabric according to the present invention and at least one of the spunlaced non-woven fabric and the flash spun non-woven fabric are combined, the typer <registered trademark> / sontara <registered trademark using hot melt bonding The composite of &gt; is suitable for products requiring wiping performance affected by tensile strength, tear strength, water absorption and moisture permeability, such as various wiper applications. On the other hand, a composite of Typer <registered trademark> / Sontara <registered trademark> using extrusion lamination is a product requiring tensile strength, tear strength, water absorption and water impermeability (water pressure resistance), for example, surgical cloth. Suitable for use. Although the non-woven fabric manufactured by DuPont was used in the description of this embodiment, it is needless to say that the non-woven fabric sheet is not limited to the product manufactured by DuPont and other non-woven fabric sheets can be used.
Further, the present invention is not limited to the above embodiment, and various modifications can be made.

[0026]

[Table 4]

In the third embodiment, as in the second embodiment, an extrusion lamination method is used to make an intermediate layer made of DuPont spunbonded nonwoven fabric TYPER 3267 <registered trademark> by flash spinning manufactured by DuPont. Non-woven Tyvek 1422A <registered trademark> is used for typer <registered trademark>
It is laminated and bonded in a three-layer structure sandwiching the intermediate layer. The three layers of non-woven fabric are laminated by lamination using a thermoplastic resin such as heat-melted polyethylene, polypropylene, or a copolymer thereof.

Similar to that described in the second embodiment, the typer 3267 delivered from the unwinding roll 3267.
<Registered trademark> or Tyvek 1422A <registered trademark> A low density polyethylene resin heated and melted at a temperature of 250 ° C to 300 ° C is extruded from a T-die, and at the same time, Tyvek 1422A <registered trademark> or Typer 3267 <
The registered trademark> is supplied to Tyvek 142
2A <registered trademark> or typer 3267 <registered trademark> will be attached. Next, a bonded composite of Tyvek 1422A <registered trademark> / Typer 3267 <registered trademark> obtained by the above-mentioned treatment or Tyvek 1422A <registered trademark> which is a surface layer of the second flash-spun nonwoven fabric.
Is a composite type of low-density polyethylene resin that is heated and melted in the same manner as above while being fed from the unwinding roll.
3267 <registered trademark> side or Tyvek 1422A <registered trademark> extruded and supplied from another direction Tyvek 1422A <registered trademark> or Tyvek 1422A <registered trademark> / typer 3267 <registered trademark> composite compound Is pasted with. The three-layer composite of Tyvek <registered trademark> / Typer <registered trademark> / Tyvek <registered trademark> thus obtained was passed through a cooling roll in the same manner as in Example 2 and wound in the winding section. Taken. The thickness of the adhesive layer of each adhesive portion forming the three-layer structure is approximately the same as in the second embodiment. In this embodiment, Tyvek is relatively soft and flexible as a flash-spun nonwoven fabric 1
Although 422A <registered trademark> was used, other tough type Tyvek 1056D <registered trademark> can also be used.

In another embodiment (fourth embodiment), three different kinds of non-woven fabrics, which are a spunlace nonwoven fabric, a spunbonded nonwoven fabric and a flash spun nonwoven fabric, are applied by using the extrusion lamination method as in the third embodiment. It is a combined composite. An intermediate layer consisting of DuPont spunbonded nonwoven typer 3267 <registered trademark> is laminated and bonded to a three-layer structure that is sandwiched between the company's spunlaced nonwoven fabric Sontara K835 <registered trademark> and its flash-spun nonwoven fabric Tyvek 1443R <registered trademark>. To do. Similar to the third embodiment, the three layers are laminated and laminated by using a thermoplastic resin such as polyethylene which is heated and melted.
For example, using a method similar to that described in the third embodiment, Typer 3267 and Tyvek 14
43R <registered trademark> is laminated by lamination using a low density polyethylene resin as an adhesive. Next, Sontara K835 <registered trademark> is attached to the composite on the side where the typer is laminated by the same extrusion lamination method, and finally Sontara <registered trademark> / Typer <registered trademark> / Tyvek < A registered trademark> composite having a three-layer structure is obtained.

Table 5 shows the characteristics of the non-woven fabric composites according to the present invention of the third and fourth embodiments, which are different from the two-layer non-woven fabric composites of the first and second embodiments. It can be seen that good improvements in tensile strength, tear strength, water resistance and water absorption can be obtained. Therefore, the non-woven fabric composite of the fourth embodiment has the same tensile strength, tear strength, water absorption and water impermeability (water pressure resistance) as the second embodiment.
It is suitable for, for example, a surgical cloth application.

[0031]

[Table 5]

Although the present invention has been specifically described based on the embodiments (examples), the present invention is not limited to the above-mentioned embodiments (examples), and various modifications can be made without departing from the scope of the invention. It goes without saying that you can do it.

[0033]

As described above, the non-woven fabric composite of the present invention is combined with the spunbonded non-woven fabric and at least one of the spunlaced non-woven fabric and the flash-spun non-woven fabric to obtain tensile strength, tear strength and water resistance. Since it exhibits excellent properties in terms of water absorbency and moisture permeability, it can be used for new uses of nonwoven fabrics, in particular for various wipers or surgical cloths.

Claims (3)

[Claims] 1. A layer of a spunbonded non-woven fabric using polypropylene filament, synthetic organic fiber, wood pulp,
A nonwoven fabric composite comprising a spunlaced nonwoven fabric using rayon, cotton or a mixed fiber thereof and / or a layer of a nonwoven fabric formed by flash spinning using polyolefin. 2. A layer of spunbonded non-woven fabric using polypropylene filament, synthetic organic fiber, wood pulp,
The nonwoven fabric composite according to claim 1, wherein the nonwoven fabric composite is formed by laminating layers of spunlace nonwoven fabric using rayon, cotton or a mixed fiber thereof. 3. A layer of non-woven fabric made by flash spinning using polyolefin is laminated on a layer of spun-bonded non-woven fabric using polypropylene filament, and synthetic organic fiber, wood pulp,
A non-woven fabric composite having a three-layer structure in which layers of spun-laced non-woven fabric using rayon, cotton, or a mixed fiber thereof, or non-woven fabric by flash spinning using polyolefin are laminated.