TWI627321B - Polypropylene non-woven fabric, manufacturing method thereof and sanitary material - Google Patents

Abstract

The present invention is a nonwoven fabric characterized in that it comprises a non-woven fabric of fibers having a main component of propylene, and the fiber has an MFR of 30 g/10 min or more and 65 g/10 min or less, and the average single yarn fineness of the fiber is 0.5 dtex or more and 3.5 dtex or less, the basis weight of the nonwoven fabric is 5 g/m ² or more and 40 g/m ² or less, and the thermocompression bonding area ratio of the nonwoven fabric is 5% or more and 15% or less, and at a hot plate temperature of 136. The heat-sealing strength of the nonwoven fabric measured under the condition of °C was 6 N/25 mm or more.

Description

Polypropylene non-woven fabric, manufacturing method thereof and sanitary material

The present invention relates to a nonwoven fabric comprising polypropylene-based fibers. More specifically, the present invention relates to a spunbonded nonwoven fabric comprising a polypropylene-based fiber which is excellent in heat-sealing property and flexibility of a top sheet, a back sheet, and a side pleat portion of an absorbent article for use in a sanitary material.

In recent years, the popularity of disposable diapers has been remarkable, and the output has also increased dramatically. As a disposable diaper in such an environment, the loss of the production line and the stability of the quality are more important. In the diaper production line, a diaper product is produced by laminating a plurality of raw materials by heat-sealing bonding by heat bonding, heat lamination, hot melt coating, or the like. In particular, the pants-type diaper is welded to the side by heat sealing, and the strength at the time of wearing is not required to be broken. In the past, in order to obtain the strength that does not break during wearing, the temperature at the time of heat sealing welding is sufficiently melted to cope with it, but there is a defect that the sealing portion is hard. In order to solve this defect, a low melting point polymer fiber such as polyethylene is compounded with a polypropylene polymer to improve heat sealability. That is, sufficient heat sealability cannot be achieved by using a single component of a polypropylene system.

On the other hand, the spunbonded nonwoven fabric is produced by melting the raw material polymer by heat and spinning by spinning from a spinning head, so that the viscosity of the molten state of the polymer becomes an important element for spinnability. . The viscosity in the molten state is determined by the combination of the MFR (melt mass flow rate) of the polymer and the spinning temperature. However, in the prior art, the fineness, strength, and spinning time of the fiber obtained only by spinning The viscosity of the polymer in a molten state is selected as the stability, for example, if it is a polypropylene resin, it is spun at about 230 ° C, depending on the MFR of the polymer used, and the fiber is not easily cut according to the spinning. , determine the spinning temperature. For example, when the temperature at the time of spinning is lowered, the viscosity of the polymer in a molten state becomes high, and the fiber becomes thick, and the fiber of the desired fineness cannot be obtained. Further, if the MFR is increased to lower the viscosity of the polymer, the molecular weight of the polymer is low, so that the strength of the spun yarn is low, and breakage often occurs during spinning, and a sufficient spunbond nonwoven fabric cannot be obtained. Further, the fibers constituting the obtained spunbonded nonwoven fabric are weak in strength, and the strength of the non-woven fabric is low. As described above, previously, the MFR of the polymer and the spinning temperature were selected only from the viewpoint of spinnability.

In other words, when the spunbonded nonwoven fabric is used as a surface material of a diaper or the like in the diaper manufacturing step, the strength of the heat seal portion, the strength of the heat seal portion when worn as a diaper, and the softness of the heat seal portion are obtained. In addition, the relationship between the heat sealability and the temperature at the time of spinning of the spunbonded nonwoven fabric is not considered (for example, refer to Patent Documents 1 and 2 below).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] International Publication No. 2007/091444

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2002-105832

The problem to be solved by the present invention is to provide a nonwoven fabric comprising polypropylene-based fibers suitable for the top sheet, the back sheet, the side gathers, and the like of the absorbent article for sanitary materials, and the heat seal portion has high strength and The heat seal portion is excellent in flexibility.

The present inventors have intensively studied and repeated experiments in order to solve the above problems, and as a result, found that the polypropylene-based spunbond nonwoven fabric can be controlled by the MFR of the polymer and the spinning temperature. The present invention is completed by producing a spunbond nonwoven fabric for a sanitary material having a high heat sealability and a heat seal portion which is not hard.

That is, the present invention is as follows.

[1] A non-woven fabric comprising: a nonwoven fabric comprising fibers having a homopolypropylene as a main component, and an MFR of the fiber of 30 g/10 min or more and 65 g/10 min or less, an average single yarn fineness of the fiber. The basis weight of the non-woven fabric is 5 g/m ² or more and 40 g/m ² or less, and the thermocompression bonding area ratio of the nonwoven fabric is 5% or more and 15% or less, and is at a hot plate temperature of 0.5 dtex or more and 3.5 dtex or less. The heat-sealing strength of the nonwoven fabric measured at 136 ° C was 6 N/25 mm or more.

[2] The nonwoven fabric according to [1] above, wherein the fiber having the homopolypropylene as a main component is a solid fiber.

[3] The nonwoven fabric according to the above [1] or [2] wherein the temperature at the time of spinning the fiber is 205 ° C or more and 210 ° C or less.

[4] The nonwoven fabric according to the above [1] or [2] wherein the temperature at which the fiber is spun is 40 ° C or more higher than the melting point of the fiber and less than 50 ° C.

[5] The non-woven fabric according to any one of the above [1] to [4], wherein a hydrophilizing agent is adhered thereto.

[6] The nonwoven fabric according to any one of [1] to [5] wherein the fiber contains a softening agent.

[7] A sanitary material formed by using the nonwoven fabric according to any one of the above [1] to [6].

[8] The sanitary material according to [7] above, which is in the form of a disposable diaper, a menstrual sanitary napkin or an incontinence pad.

The MFR of the non-woven fabric fiber containing the polypropylene-based fiber of the present invention is 30 g/10 min or more and 65 g/10 min or less, and the low-temperature heat-sealing strength is 6 N/25 mm or more. The soft-woven non-woven fabric, which is used as a diaper surface material, does not break at the heat seal portion, and the heat seal portion is soft, so it is suitable as a surface material for diapers and sanitary materials. When the polypropylene-based nonwoven fabric of the present invention is used as a surface material of a diaper, it is possible to provide a non-woven fabric surface material for sanitary materials that follows the high speed of the diaper manufacturing step, maintains sufficient heat-sealing strength, and does not harden the heat-sealed portion.

1‧‧‧ upper peeling section

2‧‧‧ Lower stripping section

3‧‧‧Heat seal

Fig. 1 is a view showing a method of measuring the heat seal strength.

Hereinafter, the present invention will be described in detail.

The fiber system having the homopolypropylene constituting the non-woven fabric of the present invention as a main component may be a polymer synthesized by a usual Ziegler-Natta catalyst. Further, it may be a polymer synthesized by a single-site active catalyst represented by a metallocene, a homopolymer of propylene, or a copolymer of propylene and another α-olefin. The other α-olefin is a carbon number of 3 to 10, and specific examples thereof include propylene, 1-butene, 1-pentene, 1-hexane, 4-methyl-1-pentene, and 1-octane. Alkene and the like. Further, it may be an ethylene random copolymer polypropylene having an ethylene content of less than 2%, preferably less than 1%. These may be used alone or in combination of two or more. It is preferred to use one type alone. Alternatively, it may be a core sheath fiber having a polyolefin resin as a surface layer. Further, the fiber shape is not only a normal circular fiber but also a special form of fiber such as a crimped fiber or a shaped fiber. Among them, from the viewpoint of strength and dimensional stability, fibers having a homopolypropylene as a main component are required.

In addition, as for the fiber having a homopolypropylene as a main component, the lower limit of MFR is 30 g/10 min or more, more preferably 40 g/10 min or more, further preferably 53 g/10 min or more, and the upper limit is 65 g/10 min or less. Preferably, it is 60 g/10 minutes or less. When the MFR is within this range, the fluidity of the resin is good, and the nonwoven fabric is excellent in flexibility, and the fiber is not broken even in the fineness of the fiber, so that the nonwoven fabric can be stably produced. MFR is based on JIS-K7210 "Melting-Molded Plastics Melt Mass Flow Rate (MFR) and Melt Volume Flow) Table 1 of the test method of the rate (MVR), the test temperature of 230 ° C, and the test load of 2.16 kg were measured and determined.

Among the fibers constituting the homopolypropylene of the non-woven fabric of the present invention as a main component, a nucleating agent, a flame retardant, an inorganic filler, a pigment, a coloring agent, a heat-resistant stabilizer, an antistatic agent and the like may be formulated depending on the purpose.

As a joining method in which a non-woven fabric is produced by joining fibers having a homopolypropylene as a main component, a partial thermocompression bonding method, a hot air method, a bonding using a molten component (hot melt) method, and various other methods are used. In particular, partial thermocompression bonding is preferred.

In the thermocompression bonding of the nonwoven fabric of the present invention, the thermocompression bonding area ratio is 5% or more and 15% or less in terms of strength retention and flexibility.

Further, the partial thermocompression bonding process of the present invention can be carried out by the ultrasonic method or by heating the embossing roller between the embossing rolls, thereby integrating the surface and the inside, for example, a needle dot shape, an elliptical shape, a diamond shape. The floating pattern such as a rectangular shape or a twill shape is scattered over the entire surface of the non-woven fabric. From the viewpoint of productivity, it is preferred to use a heated embossing roll.

However, in the fusion bonding by heat, depending on the temperature at the time of spinning of the spunbonded nonwoven fabric, there is a problem that the heat-sealed welded portion is insufficiently welded and sufficient strength cannot be obtained. Further, when the heat-sealed welded portion is used to obtain strength and is welded by heat of a higher temperature, the heat-sealed portion is hardened to impair the flexibility or the fracture is caused by the difference in rigidity between the sealed portion and the unsealed portion.

The present inventors have found that the heat-sealing property at a low temperature is high in the range in which the spinning temperature of the polymer resin which has not been previously selected is low in the viewpoint of spinnability. Spunbonded nonwoven fabric, whereby the strength of the heat-sealed welded portion is surprisingly maintained, and the heat-sealed portion is hardened without impairing flexibility, and it is found that the MFR of the polymer is appropriately combined with the spinning temperature, thereby being present A region in which the spinning property, the fineness and the strength are balanced, and a spunbonded nonwoven fabric which is suitable as a surface material for a non-woven fabric for sanitary materials, which has a sufficient heat-sealing strength and which does not become hard, is successfully obtained. Also, this hair The heat-sealing property of the woven fabric of the woven fabric at a low temperature shows a high value, so that the diaper manufacturing step can be speeded up.

The spunbonded nonwoven fabric of the present invention has an excellent heat sealability of 6 N/25 mm or more as measured by the following method. When the heat-sealing strength is 6 N/25 mm or more, the speed of the diaper manufacturing step is increased, and even if the heat is sealed at a low temperature and a short-time heat-sealing at the time of heat sealing, sufficient heat-sealing strength can be maintained, which is preferable. The heat seal strength is preferably 7 N/25 mm or more.

The heat seal strength is achieved by controlling the MFR of the fiber containing polypropylene to the above range and controlling the temperature of the polymer at the time of spinning to an appropriate range. Regarding the temperature of the polymer at the time of spinning, a polypropylene resin is exemplified and described later.

In the present invention, by controlling the MFR value of the base polymer and the temperature of the polypropylene resin at the time of spinning to an appropriate range, it is possible to obtain a fine fineness and use which are required to exhibit sufficient flexibility as a diaper application. A spunbonded nonwoven fabric of sufficient strength for heat sealing engagement.

When the MFR value of the raw material polymer is small, if the temperature of the molten resin at the time of spinning is not increased, the viscosity in the molten state is high, and the fineness is not obtained, and the spinning temperature must be increased. However, since the temperature at the time of spinning is high, the heat-sealing strength is lowered by the temperature at the time of spinning, especially when the temperature is high during the manufacture of the diaper, and the heat-sealing is performed at a lower temperature. In the case, sufficient strength cannot be obtained. Moreover, if the spinning temperature is lowered, the filament elongation is inferior and the spunbonded nonwoven fabric cannot be obtained.

Further, when the MFR is too high, the spinning temperature at the time of spinning can be made low, but the molecular weight of the polymer is low, so that the strength of the yarn constituting the spunbonded nonwoven fabric is lowered, and it is not possible to obtain sufficient heat sealing. Strength.

The inventors of the present invention have studied a method for solving the above problems, and as a result, a polymer having a MFR of a raw material polymer of 20 g/10 min or more and 68 g/10 min or less is used, and the spinning temperature is appropriately controlled in consideration of the MFR of the base polymer. Thereby obtaining the MFR of the fiber is 30 A spunbonded nonwoven fabric of g/10 minutes or more and 65 g/10 minutes or less, and a nonwoven fabric having a fine fiber, a soft fiber, and excellent heat sealing strength is obtained by the nonwoven fabric.

The average single yarn fineness of the fiber comprising the polypropylene-based polymer constituting the nonwoven fabric of the present invention is 0.5 dtex or more and 3.5 dtex or less, preferably 0.7 dtex or more and 3.2 dtex or less, more preferably 0.9 dtex or more and 2.8 dtex or less. Further, it is preferably 0.9 dtex or more and 2.5 dtex or less. From the viewpoint of spinning stability, it is preferably 0.5 dtex or more, and the finer the fineness, the more the subsequent points of the nonwoven fabric are. Therefore, the higher the strength, the better the flexibility. Since it is mainly used for sanitary materials, it is preferably 3.5 dtex or less from the viewpoint of the strength of the non-woven fabric.

The basis weight of the nonwoven fabric of the present invention is 5 g/m ² or more and 40 g/m ² or less, preferably 10 g/m ² or more and 30 g/m ² or less, more preferably 10 g/m ² or more and 25 g/m ² or less. Further, it is preferably 10 g/m ² or more and less than 23 g/m ² , more preferably 10 g/m ² or more and less than 20 g/m ² . Regarding the basis weight of the non-woven fabric, the thinner the softness, the better, and it can be preferably used as a sanitary material. If it is 5 g/m ² or more, it satisfies the necessary strength requirements for the non-woven fabric for sanitary materials. If it is 40 g/m ² or less, the softness of the nonwoven fabric for sanitary materials is satisfied, and the impression of being very thick in appearance is not caused.

The nonwoven fabric of the present invention preferably has an elongation at break of 30% or more. When the elongation at break is less than 30%, the nonwoven fabric is hard and the flexibility is poor. Moreover, when the elongation at break exceeds 50%, the stability of the nonwoven fabric is inferior, and when the crimping step in the production of the nonwoven fabric or the manufacturing process of the diaper is applied, the stretching is caused, and the problem of shrinkage or the like may occur.

Hydrophilizing agents can also be used in the nonwoven fabric of the present invention. As the hydrophilizing agent, a high-alcohol, a higher fatty acid, an alkylphenol or the like may be added to a nonionic active agent of ethylene oxide or an alkyl phosphate in consideration of safety to a human body, safety in a step, and the like. An anionic active agent such as a salt or an alkyl sulfate is preferably used singly or as a mixture.

The amount of the hydrophilizing agent to be applied varies depending on the desired properties, and is usually preferably 0.1% by weight or more and 1.0% by weight or less, more preferably 0.15% by weight or more, based on the fiber. It is 0.8% by weight or less, more preferably 0.2% by weight or more and 0.6% by weight or less. When the amount is within this range, the hydrophilic property of the top sheet as a sanitary material is satisfied, and workability is also improved.

As a method of applying the hydrophilizing agent, a diluted hydrophilizing agent is usually used, and an existing method such as a dipping method, a spray method, a coating method (contact coater, gravure coater), or the like may be employed, and preferably The pre-mixed hydrophilizing agent is diluted with a solvent such as water and applied as needed.

If the hydrophilizing agent is diluted and coated with a solvent such as water, a drying step is necessary. As the drying method at this time, a known method using convection heat transfer, conduction heat transfer, radiation heat transfer, or the like can be employed, and drying using hot air or infrared rays or a drying method using thermal contact can be used.

In the present invention, a softening agent may be added to the fiber containing the homopolypropylene as a main component. The softening agent is preferably an ester compound, and more preferably an ester compound of a 3 to 6-valent polyol and a monocarboxylic acid.

Examples of the 3 to 6-valent polyol include a trivalent polyol such as glycerin or trimethylolpropane, a tetravalent polyol such as pentaerythritol, glucose, sorbitan, diglycerin or ethylene glycol diglyceride, and the like. A pentavalent polyhydric alcohol such as glycerin or trimethylolpropane diglyceryl ether, or a hexavalent polyhydric alcohol such as sorbitol, tetraglycerin or dipentaerythritol.

Examples of the monocarboxylic acid include octanoic acid, dodecanoic acid, myristic acid, octadecanoic acid, behenic acid, hexadecanoic acid, octadecenoic acid, and docosaenoic acid. , monocarboxylic acid such as isostearyl acid, alicyclic monocarboxylic acid such as cyclohexanecarboxylic acid, aromatic monocarboxylic acid such as benzoic acid or methylbenzenecarboxylic acid, hydroxypropionic acid, hydroxyoctadecanoic acid, and hydroxyl group A hydroxyaliphatic monocarboxylic acid such as octadecenoic acid or a sulfur-containing aliphatic monocarboxylic acid such as alkylthiopropionic acid.

The ester compound does not need to be a single component, and may be a mixture of two or more kinds, and may be a fat or oil derived from a natural product. Among them, an ester compound containing an unsaturated fatty acid is easily oxidized and is easily oxidized and deteriorated during spinning, and thus is preferably a saturated aliphatic monocarboxylic acid or aromatic single. carboxylic acid. Since the fats and oils derived from natural products are odorless and stable compared with the raw material oil, it is preferable to use an ester compound obtained by hydrogenation.

As the ester compound, a monocarboxylic acid preferably has a relatively large molecular weight and a high lipophilicity. When the lipophilic property is high, the amorphous portion of the fiber containing the polypropylene-based polymer enters the amorphous portion, which hinders crystallization, and the amorphous region increases, so that the effect of lowering the bending softness is obtained.

In order to obtain this effect, the melting point of the ester compound is preferably 70 ° C or higher, more preferably 80 ° C or higher and 150 ° C or lower. Where the melting point of the ester compound is broad and has a range, the melting point means the average melting point. Further, other components may be mixed in the ester compound, for example, an ester compound having a melting point of less than 70 ° C or other organic compound.

The content of the ester compound as the softening agent is preferably 0.3% by weight or more and 5.0% by weight or less based on the fiber containing the polypropylene-based polymer. Regarding the ester compound, even if a small amount is added, the flexibility of bending or the ease of sliding are remarkably improved, and even if the content is increased, no improvement in performance comparable to the content is observed. Therefore, in view of spinnability and fuming property, it is preferably 5.0% by weight or less, more preferably 0.5% by weight or more and 3.5% by weight or less, still more preferably 0.5% by weight or more and 2.0% by weight or less.

The nonwoven fabric of the present invention is produced by the spunbond (S) method. It is better to increase the dispersing ability by stacking SS, SSS, and SSSS. Further, depending on the purpose, the spun (S) fiber and the melt-blown (M) fiber may be laminated, or may be a structure in which the laminate is SM, SMS, SMMS, or SMSMS.

The spinning temperature of the spunbond of the present invention is 190 ° C or more and 225 ° C or less, preferably 200 ° C or more and 220 ° C or less, more preferably 205 ° C or more and less than 215 ° C, in the case of a polypropylene resin. Further, it is preferably 205 ° C or more and 210 ° C or less. When the spinning temperature is 225 ° C or less, the surface of the spinning head caused by the decomposition of the resin is less contaminated, and the occurrence of breakage due to the lower viscosity of the resin can be suppressed. Moreover, when the spinning temperature is high, the produced nonwoven fabric has a low strength due to the influence of the resin decomposition product, and tends to be easily broken during processing. When the spinning temperature is 190 ° C or more, it is possible to suppress the breakage of the resin due to the high viscosity of the resin, thereby suppressing The resin leaks due to the high pressure in the spinning head during spinning.

Further, the temperature at the time of spinning the above fibers is preferably a temperature higher than the melting point of the fibers by 40 ° C or more and less than 50 ° C.

The present inventors have found that when used as a surface material of a diaper, in order to maintain sufficient strength without rupture during wearing, and to prevent the heat-sealed portion from becoming hard and impairing flexibility, it is necessary to have a lower strength at the time of low-temperature heat sealing. It is high, and in order to improve the adhesion strength at the time of low-temperature heat sealing, it is effective to control the temperature history in the manufacturing step of the spunbonded nonwoven fabric to be low.

In order to improve the adhesion strength at the time of low-temperature heat sealing, it is effective to reduce the crystal size of the fiber to be easily softened and melted by heat, and on the other hand, in the case where a large number of crystals of a small size are present, the fiber as a whole is heat-sealed. The heat of the part is contracted, and the heat seal portion shrinks or hardens to impair the softness. On the other hand, when the crystallite size is large, the crystal portion hardly suppresses the action of the molecules and suppresses shrinkage, but sufficient strength cannot be obtained at the time of low-temperature heat sealing. In the present invention, it is presumed that the spinning can be carried out so as to become a specific fiber MFR in a temperature range which has not been noticed so far, and reasonable crystallinity can be attained.

The spunbonded nonwoven fabric of the present invention can be preferably used for the manufacture of sanitary materials. As the sanitary material, disposable diapers, menstrual sanitary napkins or incontinence pads are preferably used, preferably used for the top sheet of the surface, the outer side. The bottom sheet, the side wrinkles, and the like.

Moreover, the use of the nonwoven fabric of the present invention is not limited to the above applications, and can be used, for example, in a mask, a furnace, a tape base fabric, a waterproof sheet base fabric, a patch base fabric, a band-aid base fabric, a packaging material, and a wiping product. , medical robes, bandages, clothing, skin care sheets, etc.

[Examples]

Hereinafter, embodiments of the present invention will be specifically described by way of examples and comparative examples, but the present invention is not limited to the following examples.

Furthermore, the evaluation methods of various characteristics used in the examples and comparative examples are as follows The physical properties obtained are shown in Table 1 below.

1. Average single yarn fineness (dtex)

10 cm of both ends of the nonwoven fabric to be produced was removed, and a test piece of 1 cm square was sampled in the width direction in a substantially five-division manner, and 20 diameters of each fiber were measured by a microscope, and the average single yarn fineness was calculated from the average value. Further, the density of polypropylene was set to 0.91 g/cm ³ .

2. Unit weight (g/m ² )

According to JIS-L1906, five test pieces of 20 cm in the longitudinal direction (MD direction) and 5 cm in the lateral direction were arbitrarily taken, and the mass was measured, and the average value was converted into the weight per unit area.

3. Elongation at break (%)

According to JIS L-1906, the ends of the non-woven fabric sample were removed by 10 cm, and the sample having a width of 5 cm and a length of 20 cm was cut into 5 parts in the same manner in the width direction, and the tensile tester was used to hold the sample at a clamping interval of 10 cm. The measurement was carried out at a speed of 30 cm/min. Regarding the elongation at break, the elongation at break of the sample was measured. Five samples were measured longitudinally, and the measured values were averaged to obtain the elongation at break in the longitudinal direction.

4. Heat seal strength

Two samples of 25 mm in width and 20 cm in length were cut out, and the sample was subjected to a hot plate heating type heat sealing test apparatus at a hot plate temperature of 136 ° C, a heat sealing pressure of 70 Kgf/cm ² , and a time of 1 second. Heat sealed. The heat-sealed portion was peeled off in the up-and-down direction by about 5 cm (longitudinal direction), and as shown in Fig. 1, it was attached to a fixed-length tensile tester at a 180-degree peeling manner at a clamping interval of 10 cm and a stretching speed of 10 cm/ The peel strength was measured in minutes. In Fig. 1, 1 is a heat-sealing sample upper peeling portion, 2 is a lower peeling portion, and 3 is a heat seal portion. The measurement was measured longitudinally at 3 points and expressed as the average of the maximum intensities.

5. Evaluation of the strength of the heat seal according to the diaper wearing test

An adult shorts-type diaper was produced using the obtained spunbonded nonwoven fabric, and 10 males of the standard body type were subjected to the wearing and unloading operation once per hour, and a total of 5 hours of wearing evaluation was performed. The wearing test was terminated at the stage where the heat seal portion was broken, and the average value of the maximum number of times of wear and tear of the 10 wearers was obtained.

6. Texture and appearance evaluation of heat seal

An adult shorts-type diaper was produced using the obtained spunbonded nonwoven fabric, and the texture and appearance of the heat-sealed portion were evaluated for the sensory evaluation. In the evaluation, the texture was rated as "hard" or "soft", and the appearance shrinkage was evaluated. In the case where the same evaluation is 2/3 or more among the 10 evaluators, the evaluation is adopted, and if this is not the case, it is considered that there is no difference.

[Example 1]

The polypropylene resin having a MFR of 60 g/10 min (measured according to JIS-K7210 at a temperature of 230 ° C and a load of 2.16 kg) by a spunbond method has a nozzle diameter of 0.4 mm and a single-hole discharge amount of 0.56 g/min·Hole. The spinning temperature was 205 ° C, and the filament group was drawn using a high-speed air stream pulling device using air jet to prepare a long fiber fabric having an average single yarn fineness of 1.5 dtex.

Then, the obtained fabric was passed between a smoothing roller and an embossing roller (pattern specification: circular diameter of 0.425 mm, serration arrangement, lateral spacing of 2.1 mm, longitudinal spacing of 1.1 mm, and crimping area ratio of 6.3%) at a temperature The fibers were allowed to adhere to each other at 135 ° C and a linear pressure of 35 kgf / cm to obtain a spunbonded nonwoven fabric having a basis weight of 17 g/m ² . The evaluation results of the obtained spunbonded nonwoven fabric are shown in Table 1 together with the production conditions.

An adult shorts-type diaper was produced using the obtained spunbonded nonwoven fabric, and 10 males of the standard body type were subjected to the wearing and unloading operation once per hour, and a total of 5 hours of wearing evaluation was performed. The wearing test was terminated at the stage where the heat seal portion was broken, and the average value of the maximum number of times of wear and tear of the 10 wearers was obtained. The evaluation results are shown in Table 1. In addition, when the sensory evaluation of the texture and the appearance of the heat-sealed portion was carried out, the evaluation of the texture level of "hard" or "soft" and the appearance shrinkage were evaluated, and the same evaluation was performed for 2 or more of the 10 evaluators. This evaluation is used in the case, and if this is not the case, no difference is considered. The evaluation results are shown in Table 1.

As shown in Table 1, even if the wear and tear action is carried out up to 5 times, the heat seal portion is not worn. A crack occurs and shows sufficient strength. Further, in the evaluation of the function, the texture and appearance of the heat-sealed portion were evaluated, and the diaper was obtained without shrinking or hardening.

[Embodiment 2]

In the first embodiment, the discharge amount was adjusted to obtain a spunbonded nonwoven fabric having an average single yarn fineness of 2.0 dtex and a basis weight of 11 g/m ² . The evaluation results of the obtained spunbonded nonwoven fabric are shown in Table 1 together with the production conditions.

The adult pants-type diaper was produced using the obtained spunbonded nonwoven fabric, and the same wearing evaluation as in Example 1 was carried out. As a result, even if it was carried out 5 times, it did not break during wearing, and showed sufficient strength. In particular, in the second embodiment, in the subsequent step of the heat seal portion and the other constituent members of the diaper, although the heat seal portion has a strong adhesiveness and is not easily peeled off, a diaper having a relatively soft heat seal portion is obtained.

[Example 3]

In the first embodiment, the discharge amount was adjusted to obtain a spunbonded nonwoven fabric having an average single yarn fineness of 1.1 dtex and a basis weight of 18 g/m ² . The evaluation results of the obtained spunbonded nonwoven fabric are shown in Table 1 together with the production conditions.

The adult pants-type diaper was produced using the obtained spunbonded nonwoven fabric, and the same wearing evaluation as in Example 1 was carried out. As a result, the same results as in Example 1 were obtained.

[Example 4]

Using a polypropylene resin having an MFR of 53 g/10 min, the temperature of the spun resin was set to 210 ° C, and the same procedure as in Example 1 was carried out, and the discharge amount was adjusted to obtain an average single yarn fineness of 1.1 dtex and a basis weight of 15 g. /m ² spunbonded non-woven fabric. The evaluation results of the obtained spunbonded nonwoven fabric are shown in Table 1 together with the production conditions.

The adult pants-type diaper was produced using the obtained spunbonded nonwoven fabric, and the same wearing evaluation as in Example 1 was carried out. As a result, a diaper having sufficient strength was obtained in the same manner as in Example 1.

[Example 5]

A polypropylene resin having an MFR of 60 g/10 min was used in the same manner as in Example 4, and the discharge amount was adjusted to obtain a spunbonded nonwoven fabric having an average single yarn fineness of 1.1 dtex and a basis weight of 17 g/m ² . The evaluation results of the obtained spunbonded nonwoven fabric are shown in Table 1 together with the production conditions.

The adult pants-type diaper was produced using the obtained spunbonded nonwoven fabric, and the same wearing evaluation as in Example 1 was carried out. As a result, the heat seal portion was slightly weaker than that of Example 1, but the diaper having sufficient strength was obtained without wearing the diaper for four times.

[Embodiment 6]

A polypropylene resin having an MFR of 37 g/10 min was used in the same manner as in Example 4, and the discharge amount was adjusted to obtain a spunbonded nonwoven fabric having an average single yarn fineness of 2.0 dtex and a basis weight of 17 g/m ² . The evaluation results of the obtained spunbonded nonwoven fabric are shown in Table 1 together with the production conditions.

The adult pants-type diaper was produced using the obtained spunbonded nonwoven fabric, and the same wearing evaluation as in Example 1 was carried out. As a result, the same soft diaper as that of Example 1 was obtained.

[Embodiment 7]

The polypropylene resin having an MFR of 37 g/10 min was used, and the single-hole discharge amount was set to 0.3 g/min‧Hole. Other conditions were the same as in Example 4, and an average single yarn fineness of 1.1 dtex and a basis weight of 17 g/m were obtained. ² spunbonded non-woven fabric. The evaluation results of the obtained spunbonded nonwoven fabric are shown in Table 1 together with the production conditions.

The adult pants-type diaper was produced using the obtained spunbonded nonwoven fabric, and the same wearing evaluation as in Example 1 was carried out. As a result, the same soft diaper as that of Example 1 was obtained.

[Comparative Example 1]

A polypropylene resin having an MFR of 65 g/10 min was used, and the temperature of the spun resin was 210 ° C. Other conditions were the same as in Example 1, and a long fiber fabric having an average single yarn fineness of 1.8 dtex was obtained. Then, the obtained fabric was passed through a smoothing roll and an embossing roll (pattern specification: circular diameter of 0.425 mm, serration arrangement, lateral spacing of 2.1 mm, longitudinal spacing of 1.1 mm, crimping area ratio of 6.3%), and temperature The fibers were adhered to each other at 135 ° C and a line pressure of 15 kgf / cm to obtain a spunbonded nonwoven fabric having a basis weight of 17 g / m ² . The evaluation results of the obtained spunbonded nonwoven fabric are shown in Table 1 together with the production conditions.

The adult pants-type diaper was produced using the obtained spunbonded nonwoven fabric, and the same wearing evaluation as in Example 1 was carried out. As a result, the heat-sealed portion was broken when the third time of wear and tear.

[Comparative Example 2]

The temperature of the spun resin was 225 ° C, and the same procedure as in Comparative Example 1 was carried out, and the discharge amount was adjusted to obtain a spunbonded nonwoven fabric having an average single yarn fineness of 2.0 dtex and a basis weight of 20 g/m ² . The evaluation results of the obtained spunbonded nonwoven fabric are shown in Table 1 together with the production conditions.

The adult pants-type diaper was produced using the obtained spunbonded nonwoven fabric, and the same wearing evaluation as in Example 1 was carried out. As a result, the heat-sealed portion was broken when the second time of wearing and detaching.

[Comparative Example 3]

The temperature of the spun resin was set to 215 ° C, and the same procedure as in Example 1 was carried out, and the discharge amount was adjusted to obtain a spunbonded nonwoven fabric having an average single yarn fineness of 1.1 dtex and a basis weight of 17 g/m ² . The evaluation results of the obtained spunbonded nonwoven fabric are shown in Table 1 together with the production conditions.

The adult pants-type diaper was produced using the obtained spunbonded nonwoven fabric, and the same wearing evaluation as in Example 1 was carried out. As a result, the heat-sealed portion was broken when the third time of wear and tear.

[Comparative Example 4]

A polypropylene resin having an MFR of 53 g/10 minutes was used in the same manner as in Comparative Example 3, and the discharge amount was adjusted to obtain a spunbonded nonwoven fabric having an average single yarn fineness of 1.1 dtex and a basis weight of 17 g/m ² . The evaluation results of the obtained spunbonded nonwoven fabric are shown in Table 1 together with the production conditions.

Production and implementation of adult shorts diapers using the obtained spunbonded nonwoven fabric Example 1 is the same wearing evaluation. As a result, the heat-sealed portion was broken when the first time of wearing and detaching, and the wearing evaluation could not be performed.

[Comparative Example 5]

A polypropylene resin having an MFR of 37 g/10 min was used in the same manner as in Comparative Example 3, and the discharge amount was adjusted to obtain a spunbonded nonwoven fabric having an average single yarn fineness of 3.8 dtex and a basis weight of 17 g/m ² . The evaluation results of the obtained spunbonded nonwoven fabric are shown in Table 1 together with the production conditions.

The adult pants-type diaper was produced using the obtained spunbonded nonwoven fabric, and the same wearing evaluation as in Example 1 was carried out. As a result, the heat-sealed portion was broken when the third time of wear and tear.

[Comparative Example 6]

Using a polypropylene resin having an MFR of 100 g/10 min, the temperature of the spun resin was set to 205 ° C, and the same procedure as in Comparative Example 1 was carried out, and the discharge amount was adjusted to obtain an average single yarn fineness of 1.1 dtex and a basis weight of 17 g/ m ² spunbonded non-woven fabric. The evaluation results of the obtained spunbonded nonwoven fabric are shown in Table 1 together with the production conditions.

An adult pants-type diaper was produced using the obtained spunbonded nonwoven fabric, and as a result, the heat-sealed portion was broken when the first time of wearing and detaching, and the wearing evaluation could not be performed.

[Comparative Example 7]

The average single yarn was obtained in the same manner as in Comparative Example 3, using a polypropylene resin having an MFR of 37 g/10 min, a spinning resin temperature of 260 ° C, and a single-hole discharge amount of 0.2 g/min‧Hole. A spunbond nonwoven fabric having a fineness of 1.1 dtex and a basis weight of 17 g/m ² . The evaluation results of the obtained spunbonded nonwoven fabric are shown in Table 1 together with the production conditions.

The adult pants-type diaper was produced using the obtained spunbonded nonwoven fabric, and the same wearing evaluation as in Example 1 was carried out. As a result, the heat-sealed portion was broken when the second time of wearing and detaching.

[Comparative Example 8]

Using a polypropylene resin having an MFR of 25 g/10 min, the temperature of the spun resin was set to 260 ° C, and the same procedure as in Comparative Example 1 was carried out, and the discharge amount was adjusted to obtain an average single yarn fineness of 1.1 dtex and a basis weight of 17 g/ m ² spunbonded non-woven fabric. The evaluation results of the obtained spunbonded nonwoven fabric are shown in Table 1 together with the production conditions.

The adult pants-type diaper was produced using the obtained spunbonded nonwoven fabric, and the same wearing evaluation as in Example 1 was carried out. As a result, the heat-sealed portion was broken when the second time of wearing and detaching.

[Comparative Example 9]

A polypropylene resin having an MFR of 65 g/10 min was used, and the temperature of the spun resin was 210 ° C. Other conditions were the same as in Example 1, and a long fiber fabric having an average single yarn fineness of 1.8 dtex was obtained. Then, the obtained fabric was passed through a smoothing roll and an embossing roll (pattern specification: circular diameter of 0.425 mm, serration arrangement, lateral spacing of 2.1 mm, longitudinal spacing of 1.1 mm, crimping area ratio of 6.3%), with temperature The fibers were adhered to each other at 135 ° C and a line pressure of 15 kgf / cm to obtain a spunbonded nonwoven fabric having a basis weight of 17 g / m ² . Using the obtained spunbonded nonwoven fabric, the same wearing evaluation as in Example 1 was carried out under the conditions for the production of the adult pants-type diaper of Example 1, in order to reduce the production speed and enhance the output of the heat-sealed portion. As a result, cracking did not occur even after repeated wear and tear for 5 times, but the heat seal portion contracted and the texture became hard.

[Industrial availability]

The spunbonded nonwoven fabric of the present invention is a non-woven fabric for sanitary materials which is soft and has a high heat-sealing strength and which does not harden the heat-sealed portion, and thus can be preferably used for a top sheet, a back sheet, a side wrinkle or the like of a sanitary material.

Claims (14)

A non-woven fabric characterized in that it comprises a non-woven fabric of fibers having a homopolypropylene as a main component, and the fiber has an MFR of 30 g/10 min or more and 64 g/10 min or less, and the average single yarn fineness of the fiber is 0.5 dtex. Above the 3.5 dtex or less, the basis weight of the nonwoven fabric is 5 g/m ² or more and 40 g/m ² or less, and the thermocompression bonding area ratio of the nonwoven fabric is 5% or more and 15% or less, and the hot plate temperature is 136 ° C. The heat-sealing strength of the nonwoven fabric measured under the conditions was 6 N/25 mm or more. The non-woven fabric of claim 1, wherein the fiber having the homopolypropylene as a main component is a solid fiber. The non-woven fabric of claim 1, wherein the temperature at which the fibers are spun is 205 ° C or more and 210 ° C or less. The non-woven fabric of claim 2, wherein the temperature at which the fibers are spun is 205 ° C or more and 210 ° C or less. The non-woven fabric of claim 1, wherein the temperature at which the fibers are spun is 40 ° C or more higher than the melting point of the fibers and less than 50 ° C. The non-woven fabric of claim 2, wherein the temperature at which the fibers are spun is 40 ° C or more higher than the melting point of the fibers and less than 50 ° C. A non-woven fabric according to any one of claims 1 to 6, which is attached with a hydrophilizing agent. A non-woven fabric according to any one of claims 1 to 6, wherein the fiber contains a softening agent. A non-woven fabric according to any one of the preceding claims, wherein the fiber comprises a softening agent. A sanitary material obtained by using a non-woven fabric according to any one of claims 1 to 9. The sanitary material of claim 10, which is in the form of a disposable diaper, a menstrual sanitary napkin or an incontinence pad. A method for producing a nonwoven fabric, comprising: a method for producing a nonwoven fabric comprising fibers having a homopolypropylene as a main component, and comprising the steps of: MFR of the raw material polymer of the fiber is 30 g/10 min or more and 64 g /10 minutes or less, and the fiber at the time of spinning is 205 ° C or more and 210 ° C or less, the raw material polymer of the fiber is melt-spun to obtain a non-woven fabric; the average single yarn of the fiber constituting the non-woven fabric The fineness is 0.5 dtex or more and 3.5 dtex or less, and the basis weight of the nonwoven fabric is 5 g/m ² or more and 40 g/m ² or less, and the thermocompression bonding area ratio of the nonwoven fabric is 5% or more and 15% or less, and the hot plate is used. The heat-sealing strength of the nonwoven fabric measured at a temperature of 136 ° C was 6 N/25 mm or more. A method of producing a nonwoven fabric according to claim 12, wherein the fiber having the homopolypropylene as a main component is a solid fiber. A method of producing a nonwoven fabric according to claim 12, wherein the temperature at which the fiber is spun is 40 ° C or more higher than the melting point of the fiber and less than 50 ° C.