JP2997404B2 - Reinforced spunbond nonwoven - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a reinforced spunbonded nonwoven fabric having improved high strength, impact resistance, durability, abrasion resistance, shape retention and the like. For more information on clothing,
The present invention relates to a reinforced spunbond nonwoven fabric widely used for bedding, furniture materials, interior materials, packaging materials, medical and hygiene materials, various textile base fabrics, filter materials, and the like.

[0002]

2. Description of the Related Art Spunbonded nonwoven fabrics are widely used as a forming technique in which spun filaments are drawn, polymerized at random, and continuously connected to a web. The characteristics of spunbond nonwoven fabric are that it has good balance in the vertical and horizontal directions, flexibility,
It is excellent in bulkiness, heat retention and water permeability, does not fray, and has excellent uniformity and dimensional stability, so that secondary workability is also good. However, there is a drawback that the tensile strength, tear strength, impact resistance, durability, abrasion resistance, and the like are slightly inferior depending on the use.

[0003] As a method for remedying such a defect, there is a method of obtaining a nonwoven fabric composite sheet in which a spunbonded nonwoven fabric made of polypropylene and a plain woven fabric having a weft as a drawn tape made of polyethylene are bonded (Japanese Patent Laid-Open No. 4-333651). A method of strengthening a polyester spunbonded nonwoven fabric by bonding strip-shaped tapes in a grid pattern (Japanese Patent Laid-Open No. 4-307230). A method of laminating a twill or satin-woven web (Japanese Patent Laid-Open No. 5-254605), a method of laminating and strengthening at least two spunbond web layers and a layer of reinforcing yarn by needling (Japanese Patent Laid-Open No. No. 73655). However, any of the strength improving methods using a reinforced support found in these disclosed technologies is not sufficient in a method of laminating with a nonwoven fabric without impairing the strength of the reinforcing material, and cannot maintain the inherent characteristics of a single nonwoven fabric. And the lamination method is complicated.

[0004] Further, the applicant has proposed that at least one surface of a surface heat-fusible mesh cloth woven using a flat yarn formed from a multilayer film comprising a low melting point component and a high melting point component as a reinforcing support as a weft yarn. We proposed a non-woven laminated material made by laminating heat-fusible non-woven fabrics by heat fusion.
No.-33336), a step of heating the melting point of the heat-fusible mesh cloth to the melting point of the low-melting point component or higher, and a step of crimping the laminate of the heat-fusible mesh cloth and the heat-fusible nonwoven fabric. However, it was not sufficiently satisfactory to firmly laminate and integrate the nonwoven fabric and the reinforced support while maintaining the flexibility and bulkiness as described above. Furthermore, lamination with a nonwoven fabric with a small basis weight is inferior in mechanical stability of the nonwoven fabric and is inferior in dimensional stability such as elongation at the time of processing. There are problems with the above because they are not preferred or workability is reduced.

[0005]

Therefore, in the present invention, the spunbonded nonwoven fabric is excellent in flexibility, bulkiness, heat retention, water permeability, non-fraying, uniformity, etc. while achieving the purpose of strengthening. The object of the present invention is to obtain a simple and economically satisfactory one.

[0006]

According to the present invention, a spunbonded nonwoven fabric formed of a thermoplastic resin is laminated on both surfaces of a reinforced support layer by a specific method, whereby the spunbonded nonwoven fabric is characterized in the longitudinal and transverse directions. Of a reinforced spunbonded nonwoven fabric that maintains the balance, flexibility, bulkiness, heat retention, water permeability, and imparts tensile strength, tear strength, impact resistance, durability, abrasion resistance, etc., and completed the present invention. That is what led to it.

According to the present invention, a multilayer film in which a first polyolefin resin is laminated as a core layer 5 and a second polyolefin resin having a lower melting point than the first polyolefin resin as an outer layer 6 on both surfaces thereof is slit and stretched. Long yarns spun and drawn with a thermoplastic resin are randomly laminated on both sides of a reinforced support 3 consisting of a coarse mesh body obtained by arranging the flat yarns 4 having a multilayer structure obtained in the manner described above and having a cross-section thermally fused at the intersection. A reinforced spunbonded nonwoven fabric characterized in that a laminated body is fused and integrated by bonding and bonding with the nonwoven web 2 positioned as described above.

[0008]

1 and 2 show a reinforced spunbonded nonwoven fabric 1 according to the present invention. This reinforced spunbond nonwoven fabric 1
The nonwoven web 2 formed by depositing spun and drawn long fibers and forming a web is positioned on both surfaces of the reinforced support 3, and is hot-pressed over the entire surface by a bonding step to be laminated and integrated. FIG. 4 shows an example of the manufacturing process. The thermoplastic resin is melted by the extruder 7, and the fiber extruded from the spinning nozzle 8 is drawn by a roller method or an air jet method by a take-off / spreading device 9 without entanglement of the drawn fiber by static electricity or air flow. The opened fibers are deposited on a net conveyor or a net drum which is the transfer device 10. The deposited fibers polymerize into random loops to form the nonwoven web 2. The above-mentioned reinforced support 3 formed in advance is laminated on the nonwoven web to be conveyed, and the nonwoven web is further laminated on the reinforced support from the second series of spunbond molding machines, and at the same time, the bonding apparatus is used. In step 11, fusion bonding is performed by thermocompression bonding or needle punching.

The long fibers constituting the nonwoven web 2 are not particularly limited, such as the cross-sectional shape and composition of the filaments, such as a core-sheath structure and a continuous yarn shape. 10dr, more preferably 1-5dr. This means that if the fineness is less than 0.1dr, the fibers will be too thin and have poor durability and will not have the characteristics of long fibers, and if the fineness exceeds 10dr, the voids of the nonwoven fabric will be large, This is because the appearance is not preferable.

[0010] The thermoplastic resin used for the long fiber includes ultra low density polyethylene, low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, polypropylene, polybutene-1, poly-4.
-Methylpentene-1, ethylene-vinyl acetate copolymer,
Examples thereof include polyolefin resins such as ethylene-ethyl acrylate copolymer, maleic anhydride-modified polyolefin, ethylene-propylene copolymer, polyvinyl chloride, polystyrene, polyester, polyamide, and polyvinyl alcohol.

The basis weight of the nonwoven web 2 is preferably 8 to 50 g / m ² , more preferably 15 to 50 g / m ² per one surface of the reinforced support 3.
It is a 30g / m ^2. If the basis weight is less than 8 g / m ² , the dispersion of long fibers is poor and the uniformity is inferior, the mechanical strength is also weak and the productivity is extremely deteriorated, which is not preferable.If the basis weight exceeds 50 g / m ² , it becomes rigid, and as a reinforcing material And the spunbonded nonwoven fabric has excellent strength such as flexibility.

The reinforced support 3 used in the present invention is a net-like body in which flat yarns 4 are used as weft strips to form openings in a coarse lattice shape.

As the reinforcing support 3 made of a non-woven fabric, a flat yarn having excellent smoothness and having a crossed portion of the process efficiently fixed by utilizing the heat-fusing property of the flat yarn 4 having a multilayer structure is used. A warp yarn group in which a large number of yarns are arranged in parallel at a predetermined interval, and a weft yarn group in which a large number of weft yarns are arranged in parallel at a predetermined interval, are arranged in a mutually orthogonal state and overlapped. In addition, a heat-sealed intersection is suitably employed.

Means for arranging the flat yarns include, for example, a device for continuously supplying a pair of ear yarns on both left and right sides, and a continuous weft passing between the ear yarns in a meandering manner. Means for arranging yarns by the device (Japanese Patent Application Laid-Open
No. 180657, JP-A-58-180658, JP-A-58-180659),
Non-woven fabric manufacturing equipment consisting of a yarn guide plate that supplies a plurality of warps at intervals and a device equipped with a weft yarn guide mechanism that feeds wefts in a direction perpendicular to the warp group (Japanese Utility Model Application No. 53-144981)
No.), a method of arranging the warp groups along the traveling direction on the transfer conveyor, and reciprocating in a direction crossing the traveling direction of the transfer conveyor to arrange the wefts in a zigzag shape (Japanese Patent Application Laid-Open No. 60-166443)
No.), a screw or helical spring, or other such yarn supporting members having a spiral guide structure of the same effect are arranged side by side on both the left and right sides, and a meandering weft is passed between them, and the warp is continuous in the cross direction to the weft. A known technique disclosed in a nonwoven fabric manufacturing apparatus (Japanese Patent Application Laid-Open No. 1-148857), which comprises a device for superimposing, etc., can be used. Instead, a hot air fusion method, a hot roll nip method, a hot plate contact method, or the like can be employed.

As shown in FIG. 3, the flat yarn 4 has a multi-layer structure in which a core layer 5 is formed of a first polyolefin resin and outer layers 6 on both front and back sides are formed of a second polyolefin resin. The flat yarn 4 is formed by shredding a three-layer film composed of a core layer and both outer layers, which are co-extruded and laminated by a multilayer T-die flat method or an inflation method, or laminated by a sequential extrusion lamination method. This is a composite flat yarn obtained by uniaxially stretching and then performing a heat treatment, wherein the stretching is performed at a temperature equal to or lower than the melting point of the polyolefin resin and equal to or higher than the softening point, and the stretching ratio is preferably 3 to 20. Times, more preferably 5 to 15 times, even more preferably 7 to 10 times.

The polyolefin resin used for the flat yarn 4 includes ultra low density polyethylene, low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, polypropylene, polybutene.
-1, homo-polymer of α-olefin such as poly-4-methylpentene-1, ethylene-propylene copolymer, ethylene-
Α-olefin copolymers such as vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and maleic anhydride-modified polyolefin. These polyolefin resins may be used alone or in combination of two or more.

Since the flat yarns 4 are arranged and intersected with the wefts to form the reinforcing support 3 of the nonwoven fabric, the fineness of the flat yarns 4 is 50 to 2,000 dr, more preferably 100 to 1,200 dr.
000dr. In other words, if the fineness is 50dr or less, the intended purpose as a reinforcing material will not be achieved due to low strength, and the fineness of 2,000d
If it exceeds r, the rigidity is large and the flexibility is lacking, and the inherent characteristics of the nonwoven fabric are lost. The thickness of the flat yarn 4 is 15 to 50 μm, more preferably 20 to 35 μm. In other words, not only is the strength insufficient when the thickness is less than 15 μm, but also the productivity of the film is extremely deteriorated in each step of film formation, slitting, and stretching. The unevenness of the nonwoven fabric is large, and the smoothness of the reinforcing material is unsuitable in terms of maintaining good printability due to the smoothness of the surface of the laminated nonwoven fabric.

Further, the lattice spacing of the flat yarn is 3 to
Preferably, it is 50 mm. In other words, when the flat yarns are arranged to be narrower than 3 mm intervals, the voids in the reinforced support become too small and the air permeability and water permeability of the nonwoven fabric are reduced. In other words, it is inferior in dimensional stability and durability.

Since the coarse mesh tends to cause misregistration and thread breakage at the peripheral edge and is inconvenient to handle during processing, it is necessary to fix the intersection. In the present invention, in order to prevent the misalignment, the course intersection portion is thermally fused to retain the coarseness,
In order for the second polyolefin-based resin to form heat fusion without losing the stretching effect of the first polyolefin-based resin, a temperature not higher than the melting point of the first polyolefin-based resin and not lower than the melting point of the second polyolefin-based resin. It is desirable to perform heat fusion within the range, and the first polyolefin-based resin and the second
The difference in melting point from the polyolefin resin is at least 5 ° C.
The temperature is preferably at least 10 ° C.

More specifically, the first polyolefin resin constituting the core layer 5 of the flat yarn 4 includes medium density polyethylene, high density polyethylene, polypropylene,
Polybutene-1, poly-4-methylpentene-1, and the like. On the other hand, as the second polyolefin resin having a lower melting point than the first polyolefin resin constituting the outer layer 6, ultra-low density polyethylene, Examples include low-density polyethylene, linear low-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, maleic anhydride-modified polyolefin, and ethylene-propylene copolymer.

In the thermoplastic resin used in the present invention, an antioxidant, a lubricant, an ultraviolet absorber, a flame retardant, an antistatic agent, a pigment, an inorganic filler may be used within a range not departing from the gist of the present invention depending on the purpose of use. And additives such as an organic filler, a crosslinking agent, a foaming agent, and a nucleating agent.

In the present invention, a reinforced spunbonded nonwoven fabric 1 is formed by laminating a nonwoven web 2 of a long fiber made of a thermoplastic resin on both sides of a grid-like reinforced support 3 to form a reinforced spunbonded nonwoven fabric 1. It is essential that the long fibers spun with a thermoplastic resin on both sides of the reinforced support 3 are drawn and polymerized at random, and then bonded to the web and fused together at the same time. That is, the reinforced support 3 is constituted. At the opening of the weft gap of the flat yarn, the nonwoven webs located on the front and back are firmly fused together as in normal web joining, and the joining surface between the nonwoven web and the reinforced support is low in the surface of the multilayer flat yarn. It is heat-fused by the melting point resin, so that there are extremely many contacts, the flat yarn of the reinforced support hardly comes off the non-woven fabric, delamination hardly occurs, and it is strong as a laminate. By forming an integrated, superior flexibility of spunbonded nonwoven fabric, bulkiness, warmth, water permeability,
It is possible to improve tensile strength, tear strength, impact resistance, durability, abrasion resistance, etc. in a well-balanced manner in the longitudinal direction while maintaining the feature of no fraying.

Further, since the non-woven web covers the front and back surfaces of the reinforced support, it is possible to prevent the non-woven fabric from being caught when the non-woven fabric is used or processed, thereby preventing damage to the non-woven fabric. It becomes a reinforced spunbonded nonwoven fabric with excellent suitability.

[0024]

[Example] High density polyethylene (density = 0.956 g / cm ³ , MFR
= 1.0 g / 10 min.) As a core layer 5, and low-density polyethylene (density = 0.924 g / cm ³ , MFR = 3.0 g / 10 min.) As an outer layer 6 on both sides of the core layer 5 by a co-extrusion blown film molding method. A multilayer film having a three-layer structure of 20 μm in outer layer / 160 μm in core layer / 20 μm in outer layer was manufactured. This multilayer film is slit, and at a stretching temperature of 100 to 115 ° C., a stretching ratio of 5 to 10
This was stretched twice and heat-treated at about 120 ° C. to form a flat yarn 4 having a three-layer structure. The flat yarns 4 were used as warp yarns, were arranged and superposed on the wefts at a predetermined yarn interval, and were heat-sealed at the intersections to constitute the coarsely reinforced net-like support 3.

Next, a reinforced spunbonded nonwoven fabric 1 was formed using the reinforced support 3 thus obtained as follows. Polypropylene (density = 0.910 g / cm ³ , MFR = 1.7 g / 10mi)
n.), linear low-density polyethylene (density = 0.925 g / c
(m ³ , MFR = 2.0 g / 10 min.), extruded from a double-structured composite spinning nozzle, stretched by the air jet method, and uniformly opened by the airflow diffusion method. The nonwoven web 2 is formed by depositing in a random loop on the conveyor to form the nonwoven web 2, and immediately before feeding to the heated embossing roll, the previously formed reinforcing support 3 is positioned in the middle and the nonwoven web 2 is polymerized from both sides. To form a reinforced spunbonded nonwoven fabric 1 which is fused and integrated with the reinforced support 3 simultaneously with the web bonding. Table 1 summarizes the structure of the reinforced spunbond together with the flat yarn and the reinforced support.

[0026]

[Table 1]

The reinforced spunbonded nonwoven fabric of each of the examples has a good balance in the weft direction and improved mechanical strength.
There is hardly any decrease in air permeability, and the resulting nonwoven fabric is excellent in flexibility, bulkiness, heat retention, and water permeability, has no fiber fraying, and has a smooth surface and good printability.

As a comparative example, 1) A basis weight obtained by web bonding the same nonwoven web used in Example 2 to one surface of the reinforced support used in Example 2 by bonding.
g / m ² spunbonded nonwoven fabric alone and thermocompressed with a calender roll, and 2) the same nonwoven web used in Example 2 on both sides of the reinforced support used in Example 2. Weight obtained by web bonding by bonding
g / m ² spunbonded non-woven fabric alone was laminated on the front and back sides and thermocompressed with a calender roll.
Reinforced spunbonded nonwoven fabric.

The comparative example is a laminate formed by laminating a nonwoven web having the same single-fiber fineness and the same total basis weight as in Example 2 and a similar reinforced support. Although it is effective in increasing the strength while holding, the nonwoven fabric and the reinforced support, or the nonwoven fabric are relatively easily peeled off by appropriate hand massage, and in addition, it lacks flexibility. Thus, the superiority of the present invention was clearly recognized.

[0030]

The reinforced spunbonded nonwoven fabric obtained according to the present invention is obtained by arranging a nonwoven web on both front and back sides with a reinforced support as a center and then laminating the nonwoven web through a bonding process. The spunbonded nonwoven fabric has the flexibility, no fraying, excellent bulkiness, excellent heat retention, excellent water permeability, and excellent advantages such as excellent uniformity and dimensional stability. Taking advantage of the reinforcement function of the reinforced support, high strength, impact resistance, durability, abrasion resistance, form retention, etc. are provided, clothing, bedding, furniture materials, interior materials, packaging materials, medical care -Widely used for sanitary materials, various textile base fabrics, filter materials, etc.

[Brief description of the drawings]

FIG. 1 is a partially broken partial plan view of a reinforced spunbonded nonwoven fabric of the present invention.

FIG. 2 is a partial sectional view of the reinforced spunbonded nonwoven fabric of the present invention.

FIG. 3 is a partial cross-sectional view of a flat yarn constituting a reinforced support used in the reinforced spunbonded nonwoven fabric of the present invention.

FIG. 4 is a manufacturing process diagram of the reinforced spunbonded nonwoven fabric of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reinforced spun bond nonwoven fabric 2 Non-woven web 3 Reinforced support 4 Flat yarn 5 Core layer 6 Outer layer

Claims (1)

(57) [Claims] 1. A multi-layer film in which a first polyolefin-based resin is used as a core layer 5 and a second polyolefin-based resin having a lower melting point than the first polyolefin-based resin is laminated on both surfaces as an outer layer 6 and slit and stretched. Flat fibers 4 having a multilayer structure obtained were arranged in a weft manner, and continuous fibers spun and stretched with a thermoplastic resin were randomly laminated on both sides of a reinforcing support 3 composed of a net-like body having a coarse texture in which the intersections were thermally fused. A reinforced spunbonded nonwoven fabric characterized in that the laminate is fused and integrated by bonding and bonding with the nonwoven web 2 positioned.