JP2001303421A - Thermoplastic composite nonwoven fabric and textile products using the same - Google Patents

Abstract

(57) [Summary] [PROBLEMS] A thermoplastic composite nonwoven fabric having good operability, excellent soft texture and fuzz resistance, and sufficient and sufficient nonwoven fabric strength, and an absorbent article and a wiper using the same. To provide textile products. A thermoplastic resin (B) having a melting point higher than that of the thermoplastic resin (A) is provided on both surfaces of a nonwoven fiber aggregate (I) using the thermoplastic resin (A) as a raw material resin. A thermoplastic composite nonwoven fabric on which a nonwoven fiber aggregate (II) is laminated, wherein the thermoplastic composite nonwoven fabric is bonded by point thermocompression bonding, and the point thermocompression bonding area ratio is 4 to 4% with respect to the total nonwoven fabric area. 30% thermoplastic composite non-woven fabric.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thermoplastic composite nonwoven fabric and a fiber product using the same.

[0002]

2. Description of the Related Art Nonwoven fabrics using polyolefin heat-fusible fibers are preferred for their soft texture and high strength of nonwoven fabrics, and are used for sanitary materials such as disposable diapers and sanitary products. Generally, a heat treatment method for forming a heat-fusible fiber into a nonwoven fabric includes a hot air bonding method using a suction band dryer or a suction dryer, and a heated embossing roll having a large number of convex portions and a flat roll (smooth roll). It is roughly classified into a so-called embossing point thermocompression bonding method in which a nonwoven fabric is obtained by introducing a web therebetween. In particular, the latter point thermocompression bonding method is superior in productivity as compared with the hot air bonding method, and therefore is advantageous in terms of cost. However, as a recent trend, nonwoven fabrics obtained by point thermocompression processing used for surface materials of sanitary materials have a softer texture (feel).
Is required. Therefore, a method of keeping the processing temperature low, a method of reducing the point thermocompression bonding area ratio, and the like are being studied.

[0003] In the method of keeping the processing temperature low, there is a problem that the adhesion of the nonwoven fabric is insufficient and the fibers are liable to be peeled off from the bonded portion, and this causes fluffing, thereby deteriorating the fuzzing resistance. Latent (reduced wear resistance).

On the other hand, in the method of reducing the area ratio of the point thermocompression bonding, the texture is improved, but the strength of the nonwoven fabric is insufficient. In addition, the degree of area of the point thermocompression bonding was reduced, so that the degree of freedom of the fiber was increased, and the fuzz resistance was degraded.

[0005] In the method in which the point thermocompression bonding area ratio is reduced and the processing temperature is increased, the strength of the nonwoven fabric is improved, but the molten resin is fused to an embossing roll or a flat roll.
Problems such as coiling occurred, and there was a problem in long-term stable production (operability).

When a non-woven fabric made of a thermoplastic resin is used as a material of a disposable diaper top sheet, that is, a part of the child's buttocks that directly touches the non-woven fabric, the non-woven fabric having poor fuzz resistance is rubbed between the child's buttocks and the non-woven fabric. The tips of some of the constituent fibers protrude and irritate the skin, causing rash and the like. This is compared to a non-woven fabric made of long fibers.
This phenomenon is particularly common in nonwoven fabrics made of short fibers.

On the other hand, when a non-woven fabric is used as the back sheet of a disposable diaper, that is, the outermost portion of the so-called disposable diaper, which is a material for suppressing leakage of urine, etc. Due to the contact, for example, rubbing with a tatami mat, a carpet or the like, the fibers are twisted, and the basis weight of the nonwoven fabric becomes thin, which leads to leakage of urine and the like.
In addition, the twist of the fiber becomes a pill, and the pill may be put into the mouth by a child. As described above, improvement in the fuzz resistance of the nonwoven fabric is an important quality item together with the strength and texture of the nonwoven fabric, and various production methods have been proposed to supplement these.

Japanese Patent Application Laid-Open No. 5-33257 discloses that polyethylene terephthalate long fibers are provided between layers composed of long fibers (sheath-core type composite) having polyethylene terephthalate as a core component and high-density polyethylene as a sheath component. There has been proposed a laminated nonwoven fabric having a three-layer structure in which layers are present and in which the entire nonwoven fabric is partially subjected to point thermocompression bonding. In this configuration, since the polyethylene terephthalate long fibers in the middle layer are made of a resin component having a higher melting point than the fibers in the upper and lower layers, even when subjected to point thermocompression bonding, the middle layer has little adhesion between the fibers and the fibers move relatively freely. Further, in this configuration, since the fibers of the middle layer are not adhered, the flexibility of the nonwoven fabric is maintained, but the strength of the nonwoven fabric cannot be obtained, and the fibers of the upper and lower layers must be subjected to high temperature treatment. Fusion is a problem. This is due to the lack of adhesion between the layers,
When the nonwoven fabrics were rubbed, peeling between the laminations occurred, and as a result, there was a problem in the fuzz resistance.

Japanese Patent Application Laid-Open No. 8-41768 discloses a long fiber group composed of a polymer component having a melting point of at least 20 ° C. higher than that of the long fiber group A in order to compensate for this disadvantage. A laminated nonwoven fabric has been proposed in which a long fiber group C having a portion where a long fiber group A and a long fiber group B are mixed with each other is interposed between layers consisting of only B and subjected to point thermocompression bonding.

In this method, since the fibers of the long fiber group A and the long fiber group B are mixed in the long fiber group C, the separation prevention between the lamination of the long fiber C and the long fiber group A and the long fiber group B is prevented. Can be expected to be effective. However, in this method, the long fiber group A
Since the melting point difference between the long fiber group B and the long fiber group B is different, it is necessary to set the processing temperature to the high melting point side or different processing temperatures for the high melting point side and the low melting point side. However, when the temperature is adjusted to the high melting point side, the amount of heat applied to the low melting point side becomes excessive, which causes a problem of fusing to a processing apparatus. Next, when different processing temperatures are set for the high melting point side and the low melting point side, respectively, the amount of heat applied to the long fiber group C, which is the middle layer, tends to be insufficient, and there has been a problem that separation between the layers occurs. In addition, since the long fiber group C has a structure in which the long fiber group A and the long fiber group B having different melting points are mixed, the long fiber group C has a fused portion sufficient for self-adhesion and adhesion between laminations. As a result, the degree of freedom of the fiber was increased, and the strength of the nonwoven fabric was insufficient, and there was a problem in the fuzz resistance.

As described above, various methods for producing a nonwoven fabric having both the texture of the nonwoven fabric and the strength of the nonwoven fabric have been proposed, but no nonwoven fabric satisfying the fuzz resistance has been developed. Hitherto, it has been known that as a means for improving the fuzz resistance, a method of increasing the point compression area ratio of the nonwoven fabric surface is most effective. However, if the point compression area ratio is increased and the processing temperature is increased at the same time, the texture of the nonwoven fabric is not only impaired, but also the nonwoven fabric is likely to be fused to the embossing roll. In addition, the fiber received greater damage at the edge of the crimping point, the fiber was more likely to be cut, and the fuzz resistance was poor. On the other hand, there is a method of keeping the processing temperature low, but the thermal bonding inside the nonwoven fabric becomes insufficient, leading to insufficient strength of the nonwoven fabric or delamination.

As described above, when the texture of the nonwoven fabric is emphasized,
It leads to deterioration of fuzz resistance and delamination, and if emphasis is placed on fuzz resistance, there is a dilemma that operability is deteriorated due to the texture of the nonwoven fabric, fusion to the embossing roll, and winding, and a nonwoven fabric that has improved these problems is required. Had been.

[0013]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermoplastic composite nonwoven fabric and a fiber product such as an absorbent article using the same in which the above-mentioned problems have been solved.

[0014]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, have obtained a prospect that the intended purpose will be achieved by adopting the following structure.
The present invention has been completed. (1) A thermoplastic resin (B) having a melting point higher than that of the thermoplastic resin (A) is provided on both sides of the nonwoven fiber aggregate (I) using the thermoplastic resin (A) as a raw material resin. A thermoplastic composite nonwoven fabric in which a woven fiber aggregate (II) is laminated, wherein the thermoplastic composite nonwoven fabric is joined by point thermocompression bonding, and the point thermocompression bonding area ratio is based on the total area of the nonwoven fabric.
A thermoplastic composite nonwoven fabric characterized by being 4 to 30%. (2) The thermoplastic resin (A) and the thermoplastic resin (B) are the same component resin, and the thermoplastic resin (B) has a higher melting point than the thermoplastic resin (A). The thermoplastic composite nonwoven fabric according to the above item. (3) The thermoplastic resin (A) is a low-density polyethylene,
At least one thermoplastic selected from linear low-density polyethylene, high-density polyethylene, polypropylene, propylene-based terpolymer, propylene-based terpolymer, olefin-based resin, polyester, and copolyester The thermoplastic composite nonwoven fabric according to the above item (1) or (2), which is a resin. (4) The thermoplastic resin (B) is a low-density polyethylene,
At least one thermoplastic selected from linear low-density polyethylene, high-density polyethylene, polypropylene, propylene-based terpolymer, propylene-based terpolymer, olefin-based resin, polyester, and copolyester The thermoplastic composite nonwoven fabric according to the above item (1) or (2), which is a resin. (5) The non-woven fiber aggregate (I) is a conjugate fiber composed of a thermoplastic resin (A) and a thermoplastic resin (A ′) having a melting point higher than that of the thermoplastic resin (A). The thermoplastic composite nonwoven fabric according to the item 1). (6) The non-woven fiber aggregate (II) is a conjugate fiber composed of a thermoplastic resin (B) and a thermoplastic resin (B ′) having a melting point higher than that of the thermoplastic resin (B). The thermoplastic composite nonwoven fabric according to the item 1). (7) The thermoplastic composite nonwoven fabric according to the above (1), wherein the nonwoven fiber aggregate (I) and / or the nonwoven fiber aggregate (II) are long fibers. (8) The thermoplastic composite nonwoven fabric according to any one of the above (1) to (7), and a nonwoven fabric other than the thermoplastic composite nonwoven fabric, a film, a pulp sheet, a knitted fabric, and a woven fabric. A laminated composite nonwoven fabric obtained by laminating at least one type of article. (9) An absorbent article using the thermoplastic composite nonwoven fabric according to any one of (1) to (7) or the laminated composite nonwoven fabric according to (8). (10) A wiper using the thermoplastic composite nonwoven fabric according to any one of the above (1) to (7) or the laminated composite nonwoven fabric according to the above (8).

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The thermoplastic composite nonwoven fabric of the present invention comprises a thermoplastic resin (A)
A nonwoven fiber aggregate (II) using a thermoplastic resin (B) having a melting point higher than that of the thermoplastic resin (A) as a raw material resin is laminated on both surfaces of the nonwoven fiber aggregate (I) using as a raw resin. A thermoplastic composite nonwoven fabric obtained by subjecting the laminated assembly thus obtained to point thermocompression bonding, wherein the thermoplastic composite nonwoven fabric is obtained mainly by point thermocompression bonding of the thermoplastic resin (A) of the nonwoven fiber assembly (I). Are joined. That is, at the temperature at which the thermoplastic resin (B) of the nonwoven fiber aggregate (II) softens and adheres when subjected to point thermocompression bonding, the thermoplastic resin (A) in the nonwoven fiber aggregate (I) Fully melt bonded. Therefore, the nonwoven fiber aggregate (II) on the surface portion is not easily damaged by heat and does not impair the feel of the nonwoven fabric.

More specifically, the thermoplastic composite nonwoven fabric of the present invention has sufficient nonwoven fabric strength because the nonwoven fabric inner layer is adhered by the thermoplastic resin (A) of the nonwoven fiber aggregate (I). Can be suppressed. Furthermore, it also leads to prevention of peeling between nonwoven fabric laminations.

The texture of the nonwoven fabric is greatly affected by the state of adhesion of the surface of the nonwoven fabric. In particular, in the case of the point thermocompression bonding using an embossing roll, the texture largely depends on the point thermocompression bonding area ratio (projection) and the processing temperature. With general-purpose technology, when the point thermocompression bonding area ratio is reduced, the degree of freedom of the fiber on the surface of the nonwoven fabric increases, and when the processing temperature is lowered, the degree of freedom of the fiber inside the nonwoven fabric increases. It was in the downward direction.

In the thermoplastic composite nonwoven fabric of the present invention, since the middle layer between the three layers is composed of thermoplastic resin fibers having a lower melting point than the upper and lower layers, the processing temperature which does not damage the nonwoven fabric surface Even if processing is carried out, since the inside of the nonwoven fabric is sufficiently adhered, the degree of freedom of the fiber can be controlled. For this reason, in the case of the same-point thermocompression bonding area ratio, as compared with the conventional nonwoven fabric, the texture and the fuzz resistance are excellent, and the strength of the nonwoven fabric is sufficient. In addition, roll winding by the molten resin can be suppressed, and stable production (operability) can be achieved.

In producing the thermoplastic composite nonwoven fabric of the present invention, the nonwoven fiber aggregate (I) and the nonwoven fiber aggregate (II)
The reason why the point thermocompression bonding method is selected as an integrated method is that the point thermocompression bonding method is a processing method using heat and pressure compared to the hot air processing method, so that it can be processed at a temperature lower than the melting point of the thermoplastic resin to be welded. There is. That is, when the nonwoven fiber aggregate (I) and the nonwoven fiber aggregate (II) are laminated and integrated by point thermocompression bonding, the point thermocompression bonding method uses a nonwoven fiber aggregate caused by heat during point thermocompression bonding. This is most preferable because damage to (II) can be suppressed and the adhesive strength of the nonwoven fiber aggregate (I) can be sufficiently exhibited. In addition, the area of the fusion zone for point thermocompression bonding (point thermocompression bonding area ratio) is
The range is preferably 4 to 30%, more preferably 5 to 25%.
%. If the area of the fusion zone is less than 4%, delamination between nonwoven fabric laminates is concerned, and if it exceeds 30%, the texture may be reduced.

As the shape of the convex portion of the embossing roll, those engraved in various shapes can be used. For example, various shapes such as circular, elliptical, square, rectangular, parallelogram, rhombic, triangular, and hexagonal can be used as the planar shape of the tip surface of the convex portion.

In the present invention, the reason why a difference in melting point between the thermoplastic resin (A) of the nonwoven fiber aggregate (I) and the thermoplastic resin (B) of the nonwoven fiber aggregate (II) is required is as follows. Non-woven fiber aggregate during welding by point thermocompression bonding (A) (II)
The fiber damage of the nonwoven fabric can be suppressed as much as possible, and the partial thermal bonding between the laminations can be further strengthened, whereby the delamination is suppressed, and a composite nonwoven fabric having high nonwoven fabric strength can be obtained. Conversely, when the melting point of the thermoplastic resin (B) is lower than that of the thermoplastic resin (A), troubles such as deterioration of fuzz resistance at low-temperature processing and roll-wrapping at high temperature processing may occur as conventional problems. For these reasons, as the combination of resins, it is preferable that the thermoplastic resin (A) and the thermoplastic resin (B) have a difference in melting point and are the same component resin.
This combination is further effective in preventing peeling between the laminations, and is excellent in fuzz resistance.

In the present invention, the combination of the thermoplastic resin (A) and the thermoplastic resin (B) is not particularly limited as long as the difference in melting point is 1 ° C. or more, preferably 3 ° C. or more. As a combination of the thermoplastic resin (A) / the thermoplastic resin (B),
High-density polyethylene / polypropylene, low-density polyethylene / polypropylene, linear low-density polyethylene / polypropylene, a binary copolymer of propylene with other α-olefins or a terpolymer / propylene with other α-olefins Terpolymer or terpolymer, linear low density polyethylene / high density polyethylene, low density polyethylene / high density polyethylene, low density polyethylene / linear low density polyethylene, linear low density polyethylene /
Binary copolymer or ternary copolymer of propylene and other α-olefin, low-density polyethylene / binary copolymer or ternary copolymer of propylene and other α-olefin, high-density polyethylene / propylene and Binary or ternary copolymers with other α-olefins, propylene with other α-olefins
Binary copolymer or terpolymer with olefin / polypropylene, linear low density polyethylene / copolyester, low density polyethylene / copolyester, high density polyethylene / copolyester, copolyester / polyester, Nylon 6 / nylon 66 and the like can be exemplified. Among these, combinations of the same component resins having a different melting point such as polypropylene resin / polypropylene resin, polyethylene resin / polyethylene resin, polyester resin / polyester resin, and polyamide resin / polyamide resin are more preferably used because they have a large adhesive effect between layers. Can be

As the polyethylene used in the thermoplastic resin (A) and the thermoplastic resin (B) in the present invention, polyethylene resins generally used industrially are preferably used. 925 g / cm ³
Low density polyethylene with a density of 0.926 to 0.940
g / cm ³ linear low density polyethylene, density 0.9
High-density polyethylene having a melting point of 41 to 0.980 g / cm ³ can be exemplified, and among these, those having a high melting point are used as the thermoplastic resin (B). The melt flow rate (M
I: JIS K7210 value measured according to condition 4 in Table 1) is preferably in the range of 2 to 100 g / 10 minutes.

In the present invention, examples of the polypropylene used for the thermoplastic resin (A) and the thermoplastic resin (B) include homopolypropylene, propylene-based terpolymers and propylene-based terpolymers. Among them, one having a high melting point is used as the thermoplastic resin (B). The melt flow rate (MFR: JISK)
7210 (measured in accordance with condition 14 in Table 1) is preferably 2 to 150 g / 10 min, and the melting point is 120 to 165 ° C.

In the present invention, the propylene-based terpolymer and propylene-based terpolymer used for the thermoplastic resin (A) and the thermoplastic resin (B) contain propylene as a main component and a small amount of propylene. Ethylene, butene
Examples thereof include a crystalline copolymer with an α-olefin such as 1, hexane-1, octene-1, or 4-methylpentene-1. Further, the copolymer has an MFR of 2 to 150 g / 10 min and a melting point of 120 to 158 ° C. Those in the range are preferably used.
As a specific example, a propylene / ethylene binary copolymer mainly composed of propylene containing 99 to 85% by weight of propylene units and 1 to 15% by weight of ethylene units, 99 to 50% by weight of propylene units and butene-1 Propylene / butene mainly composed of propylene containing 1 to 50% by weight of a unit
84 to 9 of the binary copolymer or propylene unit
8% by weight, 1 to 10% by weight of ethylene unit, butene-1
A terpolymer of propylene / ethylene / butene-1 containing 1 to 15% by weight of a unit is exemplified.

The thermoplastic resin used in the present invention may further contain an antioxidant, a light stabilizer, an ultraviolet absorber, a neutralizing agent, a nucleating agent, an epoxy stabilizer, a lubricant within a range not to impair the effects of the present invention. If necessary, antibacterial agents, flame retardants, antistatic agents, pigments, plasticizers, and hydrophilic agents may be added. In addition, the thermoplastic composite nonwoven fabric of the present invention may be subjected to a surface treatment such as a surfactant, if necessary.

The fiber composition of the nonwoven fiber aggregate (I) of the present invention may be a single fiber of the thermoplastic resin (A), wherein the thermoplastic resin (A) component is used as a sheath component, and the thermoplastic resin (A) is used. Thermoplastic resin (A ') having a melting point higher by at least 5 ° C than the components
May be a composite fiber having a core component. Note that a thermoplastic resin similar to that used for the thermoplastic resin (A) and the thermoplastic resin (B) may be used for the thermoplastic resin (A ′).

The fiber composition of the nonwoven fiber aggregate (II) of the present invention may be a single fiber of the thermoplastic resin (B), and the thermoplastic resin (B) is used as a sheath component, and the thermoplastic resin (B) is used. Thermoplastic resin (B ') having a melting point higher by at least 5 ° C than the components
May be a composite fiber having a core component. In addition, the same thermoplastic resin as that used for the thermoplastic resin (A) and the thermoplastic resin (B) may be used for the thermoplastic resin (B ′).

The thermoplastic resin (B) of the nonwoven fiber aggregate (II) to be laminated on the upper and lower layers of the thermoplastic composite nonwoven fabric of the present invention.
It is not necessary that the resin composition of the upper and lower layers be the same resin, and the thermoplastic resin (A) of the nonwoven fiber aggregate (I) located in the middle layer
It is sufficient that the resin composition has a higher melting point than that of the thermoplastic resin, and the resin composition of the upper and lower layers may have a difference in melting point.

The laminated structure of the thermoplastic composite nonwoven fabric of the present invention may be expressed as a single fiber / nonwoven fiber aggregate (II) / nonwoven fiber aggregate (I) / nonwoven fiber aggregate (II). Single Fiber / Single Fiber, Composite Fiber / Composite Fiber / Composite Fiber, Composite Fiber / Single Fiber / Single Fiber, Composite Fiber / Composite Fiber / Single Fiber, Single Fiber / Single Fiber / Composite Fiber, Single Combinations of single fiber / composite fiber / composite fiber, composite fiber / single fiber / composite fiber, single fiber / composite fiber / single fiber, etc. can be exemplified.

Nonwoven fiber aggregate (I) used in the present invention
Short fibers or long fibers are used as the fibers of the nonwoven fiber aggregate (II). The method for producing short fibers is not particularly limited, but in the case of conjugate fibers, a parallel type, a sheath-core type, an eccentric sheath-core type, a multi-split type or the like using a spinneret having a cross section, and a known composite spinning method is used. Spinning to obtain an undrawn fiber,
This can be exemplified by a method in which the fiber is stretched, further crimped, and the fiber is cut into an appropriate length. In addition, the composite form of the fiber is preferably a concentric type because of excellent dimensional stability. In addition, a stretched fiber which is an intermediate for producing the short fiber is used, and a crimp is not applied to the stretched fiber, and a straight cut fiber (chop) or a melt-spun polymer stream is heated by a high-temperature high-pressure air stream. A method for producing fibers obtained by a known melt-blowing method, in which the web is blown, thinned, and collected and deposited on a moving collecting surface to form a web, is also a representative example of the method for producing short fibers. On the other hand, the method for producing long fibers is not particularly limited, but in the case of obtaining a conjugate fiber form, a spinneret having a cross section such as a parallel type, a sheath-core type, an eccentric sheath-core type, or a multi-split type is used. Can be manufactured by the spun bond method.

The fineness of the fibers constituting the thermoplastic composite nonwoven fabric of the present invention is not particularly limited, but is preferably 0.01 to 11 dtex in terms of texture and flexibility. The thermoplastic composite nonwoven basis weight is preferably from 5 to 40 g / m ^2, more preferably from 8~30g / m ^2. The basis weight is 5
If less than g / m ² , sufficient strength of the nonwoven fabric cannot be obtained.
/ M ² , sufficient strength of the nonwoven fabric can be obtained,
If it exceeds 40 g / m ² , it tends to have a poor feel when used for surface materials such as sanitary materials. Further, when a composite fiber is used, the composite weight ratio (sheath component / core component) is preferably in the range of 20/80 to 70/30% by weight, more preferably 40/60 to 60/40. When the sheath component is less than 20%, the heat adhesion of the obtained fiber is reduced. On the contrary, when the sheath component exceeds 70%, the core component tends to be biased with respect to the sheath component, which causes shrinkage during heat treatment. The dimensional stability tends to decrease.

The basis weight ratio of the nonwoven fiber aggregate (I) and the nonwoven fiber aggregate (II), which constitute the thermoplastic composite nonwoven fabric of the present invention, is the same as the basis weight ratio of the nonwoven fiber aggregate (I) ( The basis weight of the nonwoven fiber aggregate (II) / the basis weight of the nonwoven fiber aggregate (I)),
It is preferably 0.2 to 5. Particularly preferably, it is 0.
3-4. When the basis weight is more than 5, the nonwoven fabric has poor adhesion when heat-treated, and tends to cause problems in peeling between layers and fuzz resistance. The basis weight ratio of the upper and lower layers of the nonwoven fiber aggregate (II) is not limited to the same ratio, and can be arbitrarily selected according to the use.

In the thermoplastic composite nonwoven fabric of the present invention,
To the extent that the effect is not impaired, nonwoven fabrics other than the thermoplastic composite nonwoven fabric of the present invention, films, pulp sheets, knits, woven fabrics, and other articles can be laminated to form a laminated composite nonwoven fabric. In addition, the thermoplastic composite nonwoven fabric used at this time may be laminated alone, or may be laminated in combination of two or more. Further, the material constituting the article is not limited, and may be any material that can be used industrially, and may include a material that can be bonded to the base thermoplastic composite nonwoven fabric or a material that can be bonded. preferable.

The thermoplastic composite nonwoven fabric and the laminated composite nonwoven fabric of the present invention can be preferably used for absorbent articles, textile products such as wipers, and the like. As the absorbent article, for example, it can be particularly preferably used as a material for sanitary materials such as disposable diapers, napkins, sweat pads, sebum removing sheet materials, and hand wipes for infants and adults.

Further, as the wiper, for example, it can be preferably used as a part or the whole of household disposable rags, window wiping materials, floor wiping materials, tatami wiping materials and the like. In addition, it can be used as a disposable seat cover for airplanes and passenger vehicles, a disposable toilet seat cover, a heat insulator for clothes, a molding base material, and the like.

[0037]

The present invention will be described below in detail with reference to examples and comparative examples, but the present invention is not limited to these examples. The terms used in the examples and comparative examples and methods for measuring physical properties are as follows.

(1) Melting point of thermoplastic resin (melting point after fiber molding) MP (° C.): Measured in accordance with JIS K7122.

(2) Compression area ratio (emboss roll convex portion)%: The ratio of the convex portion to the total area of the pressure roll. (3) Area ratio of point thermocompression bonding (embossed surface side of nonwoven fabric)%: ratio of area of fusion area for point thermocompression bonding to total area of nonwoven fabric.

(3) Texture of non-woven fabric A sensory test was conducted by five panelists, and when all were judged to be soft, it was excellent, when three or more were judged soft, good, and when three or more were soft, In the case where it was judged that the sample was lacking, the result was evaluated as “impossible”.

(4) Nonwoven fabric strength (CD) From thermoplastic composite nonwoven fabric or laminated composite nonwoven fabric, M
The test piece was placed 5 cm so that D was 2.5 cm and CD was 15 cm.
Collect one sheet. This test piece was gripped at a distance of 10 cm using an autograph AGS500D manufactured by Shimadzu Corporation.
Breaking strength (cN / 2.5 at a tensile speed of 10 cm / min)
cm) was measured, and the average value of the five sheets was regarded as the nonwoven fabric strength of the CD. The machine direction (length direction) of the nonwoven fabric was MD, and the direction perpendicular to the machine direction (lateral direction) was CD.

(5) Evaluation of Fuzzing Resistance A method for evaluating the fuzzing resistance (hardness of fluffing) of the obtained nonwoven fabric is described below. The evaluation method conforms to JIS L0849-1974. A non-woven fabric sample of 4 cm x 20 cm
・ Prepare 4 CDs each. 3.5cm x 20cm in the length direction of the nonwoven fabric sample
Paste long double-sided tape. At this time, two nonwoven fabric samples on the embossed roll treated surface side and the flat roll treated surface side are prepared for each of the MD and CD. A nonwoven fabric sample was stuck on a data base of a friction tester (manufactured by Suga Test Instruments Co., Ltd.), and Kanakin No. 3 cloth (4 cm × 5
cm). Place the friction element on the non-woven fabric sample, and rub the surface of the non-woven fabric at 150 reciprocations (follicle generation and fluffing)
Is organoleptically evaluated. Judgment criteria (sensory index) A: Neither fluff nor fluff is observed. ：: Some fluffing is observed. Δ: Many fluffs and pills are observed. X: Many fluffs and multiple pills are observed.

Example 1, Comparative Example 1 A crystalline polypropylene (homopolymer) having an MFR of 10 was used as the thermoplastic resin (A ').
Using a propylene / ethylene binary copolymer having an MFR of 16, an ethylene unit of 5% by weight and a propylene unit of 95% by weight, using a spinneret having a concentric sheath-core cross section, using a known spunbond method. In, the weight ratio 50% / 50%
The amount of the composite fiber discharged from the spinneret is introduced into the air soccer and drawn and drawn, and 2d
tex long fiber (composite) is obtained, and then the long fiber group discharged from the air soccer is charged and charged with the same charge by a charging device. The obtained long fiber group was collected as a long fiber (composite) web on an endless net-shaped conveyor provided with a suction device on the back surface, and this was used as a nonwoven fiber aggregate (I). Similarly, a spinneret having a cross section of a concentric sheath core structure by a spun bond method is used, a crystalline polypropylene (homopolymer) of MFR10 is used as a thermoplastic resin (B ′), and MFR15 is used as a thermoplastic resin (B). 2% by weight,
Spinning was performed using a propylene / ethylene binary copolymer containing 98% by weight of propylene units, and the resulting web was collected as a 2dtex long fiber (composite) web, which was used as a nonwoven fiber aggregate (II). Non-woven fiber aggregate (I) laminated on middle layer and non-woven fiber aggregate (II) on upper and lower layers (Example 1), non-woven fiber aggregate (II) on non-woven fiber in middle layer An assembly (I) laminated so as to be positioned in upper and lower layers (Comparative Example 1) was subjected to a linear pressure of 20 N / mm and a compression area ratio of 10
%, Emboss roll temperature / flat roll temperature = 120
Processing was performed at a processing temperature of 120 ° C / ° C to obtain a thermoplastic composite nonwoven fabric. Example 1 has a texture, as seen in Table 1,
The nonwoven fabric was very strong and had excellent fuzz resistance. In Comparative Example 1, the strength of the nonwoven fabric was low, and the fuzz resistance was significantly poor.

Example 2 As the thermoplastic resin (A '), a crystalline polypropylene (homopolymer) of MFR10 was used, and the thermoplastic resin (A) was used.
Using a high-density polyethylene having a density of 0.959 and an MI of 13 and using a spinneret having a concentric sheath-core structure in cross section by the same spunbonding method as in Example 1, and a 2dtex long fiber (composite) web Was used as the nonwoven fiber aggregate (I). Next, a propylene / ethylene binary copolymer containing 2% by weight of an ethylene unit having an MFR of 15 and 98% by weight of a propylene unit was used as the thermoplastic resin (B ′). Using an ethylene / butene-1 / propylene terpolymer containing 3% by weight of the unit, 5% by weight of the butene-1 unit and 92% by weight of propylene, the eccentric sheath core is obtained by the same spun bond method as in Example 1. Spinning was performed using a spinneret having a cross section of a mold to obtain a 2dtex long fiber (composite) web, which was used as a nonwoven fiber aggregate (II). The nonwoven fiber aggregate (I) is laminated on the middle layer and the nonwoven fiber aggregate (II) is laminated on the upper and lower layers, and the linear pressure is 20 N / mm and the crimping area ratio is 20.
%, Emboss roll temperature / flat roll temperature = 120
Processing was performed at a processing temperature of 120 ° C / ° C to obtain a thermoplastic composite nonwoven fabric. Example 2 has a texture, as seen in Table 1,
The nonwoven fabric was very strong and had excellent fuzz resistance. Further, when the nonwoven fabric was used as a surface material of a disposable diaper for adults, it was very good as an absorbent article.

Example 3, Comparative Example 2 A thermoplastic resin (A) having a density of 0.935 and an MI of 2
Using a single component of the linear low-density polyethylene of No. 0, a long fiber web of 2 dtex was obtained by the same spunbonding method as in Example 1, and this was used as the nonwoven fiber aggregate (I).
Next, the thermoplastic resin (B) has a density of 0.959, MI
Was obtained by a spunbonding method similar to that of Example 1 using a single component of high-density polyethylene having a density of 13 and was used as a nonwoven fiber aggregate (II). Non-woven fiber aggregate (I) laminated on middle layer and non-woven fiber aggregate (II) laminated on upper and lower layers (Example 3), non-woven fiber aggregate (II) on non-woven fiber The laminate (Comparative Example 2) obtained by laminating the aggregate (I) so as to be positioned in the upper and lower layers was subjected to a linear pressure of 2
0N / mm, crimping area ratio 10%, embossing roll temperature /
Processing was performed at a processing temperature of flat roll temperature = 120 ° C./120° C. to obtain a thermoplastic composite nonwoven fabric. Example 3 is shown in Table 1.
As can be seen from the above, the texture, the strength of the nonwoven fabric, and the resistance to fuzzing were extremely excellent, and the phenomenon that the resin was fused to the embossing roll was not observed, so that stable production was possible. On the other hand, in Comparative Example 2, a problem that the resin was fused to the embossing roll occurred.

Example 4 A crystalline polypropylene (homopolymer) of MFR10 was used as the thermoplastic resin (A ').
Using a low-density polyethylene having a density of 0.918 and an MI of 24, using a spinneret having a concentric sheath-core cross section by a composite spinning apparatus, and extruding an amount so that the weight ratio becomes 50% / 50%. Spinning with setting, single yarn fineness 4.4 dt
ex was obtained. After that, the film is stretched 2.4 times with a hot roll, and after giving a mechanical crimp, it is cut to 2.2 dt.
A composite fiber of ex × 38 mm was obtained. The composite fiber was carded with a roller card machine to obtain a web, which was used as a nonwoven fiber aggregate (I). Next, using a single component of high-density polyethylene having a density of 0.959 and an MI of 13 as the thermoplastic resin (B), a 2dtex long fiber web was obtained by a spunbonding method similar to that in Example 1. Was used as a nonwoven fiber aggregate (II). The nonwoven fiber aggregate (I) is laminated on the middle layer and the nonwoven fiber aggregate (II) is laminated on the upper and lower layers, and the linear pressure is 20 N / mm and the crimping area ratio is 20.
%, Emboss roll temperature / flat roll temperature = 120
Processing was performed at a processing temperature of 120 ° C / ° C to obtain a thermoplastic composite nonwoven fabric. Example 4 has a texture, as seen in Table 1,
The nonwoven fabric was very strong and had excellent fuzz resistance.

Example 5 MFR16 was used as the thermoplastic resin (A), and a single component of a propylene / ethylene binary copolymer containing 5% by weight of ethylene units and 95% by weight of propylene units was used. A 2dtex long fiber web was obtained by the same spunbonding method, and this was used as the nonwoven fiber aggregate (I). Next, as the thermoplastic resin (B), MFR 15, propylene / ethylene / butene-containing 2% by weight of ethylene unit, 4% by weight of butene-1 unit and 94% by weight of propylene unit was used.
Using a single component of 1 terpolymer, a 2dtex long fiber web was obtained by the same spun bond method as in Example 1, and this was used as the nonwoven fiber aggregate (II) in the upper layer. Next, the same spunbonding as in Example 1 was carried out using MFR15 as the thermoplastic resin (B) and a single component of a propylene / ethylene binary copolymer containing 3% by weight of ethylene units and 97% by weight of propylene units. A 2dtex long fiber web was obtained by the method, and this was used as a nonwoven fiber aggregate (II) in the lower layer. Each is laminated so as to be positioned on the upper and lower layers of the nonwoven fiber aggregate (I), and has a linear pressure of 20 N / mm, a crimping area ratio of 20%, and an emboss roll temperature / flat roll temperature = 1.
Processing was performed at a processing temperature of 25 ° C./125° C. to obtain a thermoplastic composite nonwoven fabric. As shown in Table 1, Example 5 was very excellent in texture, nonwoven fabric strength, and fuzz resistance.

Comparative Examples 3 and 4 Using a single component of high-density polyethylene having a density of 0.959 and an MI of 13, a 2dtex long fiber web was obtained by the same spunbonding method as in Example 1, and a linear pressure of 20 N / Mm, crimping area ratio 20%, embossing roll temperature / flat roll temperature = 110 ° C./110° C. to obtain a nonwoven fabric (Comparative Example 3). Also, using the same long fiber web, emboss roll temperature / flat roll temperature = 130.
Processing was performed at a processing temperature of 130 ° C./130° C. to obtain a nonwoven fabric (Comparative Example 4). Comparative Example 3 is inferior in nonwoven fabric strength and fuzz resistance,
In Comparative Example 4, the texture was inferior, and during continuous operation, a problem occurred in which the resin was fused to the embossing roll and the nonwoven fabric was wound around the embossing roll.

Comparative Example 5 A single web of 2.2 dtex × 38 mm polypropylene single fiber collected in the same manner as the nonwoven fiber aggregate (I) of Example 4 was carded by a roller card machine, and the obtained web was obtained. As the upper layer of the laminate, 2.2 dtex × 38 m
m of high-density polyethylene single fiber is carded with a roller card machine, and the obtained web is used as a lower layer of a laminate. / 50%, carded by a roller card machine, and using the obtained web as a middle layer of lamination.
0N / mm, crimping area ratio 20%, embossing roll temperature /
Processing was performed at a processing temperature of flat roll temperature = 125 ° C./125° C. to obtain a thermoplastic composite nonwoven fabric. In Comparative Example 5, the polypropylene single fiber in the upper layer portion was insufficient in adhesion, and the fuzz resistance was poor. The nonwoven fabric strength was also low.

Example 6 When the thermoplastic composite nonwoven fabric of the present invention obtained in Example 5 was used as a window-wiping wiper, it showed very good dust adsorbing properties.

As can be seen from the examples, the thermoplastic composite nonwoven fabric of the present invention has a nonwoven fiber aggregate (I) located in the middle layer.
Since the thermoplastic resin (A) has a lower melting point than the thermoplastic resin (B) of the nonwoven fiber aggregate (II) located in the upper and lower layers, the thermoplastic resin (B) At a temperature at which the resin softens and adheres, the thermoplastic resin (A) is sufficiently fused and adhered. Furthermore, the nonwoven fiber aggregate (II) located on the surface is hardly damaged by heat, the fusion (winding) of the resin to the embossing roll is suppressed, and the nonwoven fabric has strong strength, texture, and fuzz resistance. Good and satisfactory. Furthermore, when the thermoplastic composite nonwoven fabric was used for a top sheet and / or a back sheet of a disposable diaper for children, the nonwoven fabric had no problem in fuzz resistance, was excellent in tactile sensation, and was sufficiently satisfactory.

[0052]

[Table 1]

[0053]

The thermoplastic composite nonwoven fabric of the present invention has excellent operability and has a good texture. In addition, it has excellent fuzz resistance and has practically sufficient nonwoven fabric strength.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) A61F 13/514 D04H 3/16 4L047 B32B 5/26 A61F 13/18 310Z D04H 3/00 320 3/16 A41B 13/02 E // A61F 13/49 F F term (reference) 3B029 BB02 BB05 BB07 BC02 BC05 BC06 BC07 3B074 AA02 AA08 AB01 AC03 BB01 4C003 BA02 BA08 4C098 AA09 CC07 CC10 CE05 CE06 DD10 DD25 DD26 4F100 AK01A01 AK01B01 AK01B01 AK05C AK06A AK06B AK06C AK07A AK07B AK07C AK41A AK41B AK41C AK63A AK63B AK63C AL01A AL01B AL01C BA03 BA06 BA10B BA10C BA26A BA26B BA26C BA26D BA26E BA32 DG04A DG04B DG04C DG04D DG04E DG12 DG13 DG15A DG15B DG15C DG15D DG15E GB72 JA04A JA04B JA04C JB16A JB16B JB16C JB16D JB16E JL02 YY00A 4L047 AA14 AA28 AB03 BA09 BB08 CA05 CC03 CC04 CC05 CC16

Claims (10)

[Claims] 1. The thermoplastic resin (A) is provided on both sides of a nonwoven fiber aggregate (I) using the thermoplastic resin (A) as a raw material resin.
A thermoplastic composite nonwoven fabric in which a nonwoven fiber aggregate (II) using a thermoplastic resin (B) having a higher melting point as a raw material resin is laminated, and the thermoplastic composite nonwoven fabric is joined by point thermocompression bonding. A thermoplastic composite nonwoven fabric having a point thermocompression bonding area ratio of 4 to 30% based on the total area of the nonwoven fabric. 2. The thermoplastic resin (A) and the thermoplastic resin (B) are the same component resin, and the thermoplastic resin (B)
2. The thermoplastic composite nonwoven fabric according to claim 1, wherein the nonwoven fabric has a higher melting point than the thermoplastic resin (A). 3. An olefin resin in which the thermoplastic resin (A) is a low-density polyethylene, a linear low-density polyethylene, a high-density polyethylene, a polypropylene, a propylene-based terpolymer, or a propylene-based terpolymer. The thermoplastic composite nonwoven fabric according to claim 1 or 2, wherein the thermoplastic composite nonwoven fabric is at least one thermoplastic resin selected from the group consisting of polyester, and a copolyester. 4. An olefin resin wherein the thermoplastic resin (B) is a low-density polyethylene, a linear low-density polyethylene, a high-density polyethylene, a polypropylene, a propylene-based terpolymer, or a propylene-based terpolymer. The thermoplastic composite nonwoven fabric according to claim 1 or 2, wherein the thermoplastic composite nonwoven fabric is at least one thermoplastic resin selected from the group consisting of polyester, and a copolyester. 5. The non-woven fiber aggregate (I) is a conjugate fiber composed of a thermoplastic resin (A) and a thermoplastic resin (A ′) having a higher melting point than the thermoplastic resin (A). The thermoplastic composite nonwoven fabric according to claim 1. 6. The non-woven fiber aggregate (II) is a conjugate fiber composed of a thermoplastic resin (B) and a thermoplastic resin (B ′) having a higher melting point than the thermoplastic resin (B). The thermoplastic composite nonwoven fabric according to claim 1. 7. The thermoplastic composite nonwoven fabric according to claim 1, wherein the nonwoven fiber aggregate (I) and / or the nonwoven fiber aggregate (II) are long fibers. 8. The thermoplastic composite nonwoven fabric according to any one of claims 1 to 7, and at least one selected from nonwoven fabrics other than the thermoplastic composite nonwoven fabric, a film, a pulp sheet, a knit, and a woven fabric. A laminated composite nonwoven fabric in which one type of article is laminated. 9. An absorbent article using the thermoplastic composite nonwoven fabric according to any one of claims 1 to 7 or the laminated composite nonwoven fabric according to claim 8. 10. A wiper using the thermoplastic composite nonwoven fabric according to any one of claims 1 to 7 or the laminated composite nonwoven fabric according to claim 8.