WO2019146726A1

WO2019146726A1 - Composite long-fiber non-woven fabric using eccentric sheath/core composite fibers at one or both surfaces

Info

Publication number: WO2019146726A1
Application number: PCT/JP2019/002363
Authority: WO
Inventors: 祥吾池田; 瑛大藤井; 一哉税所; 矢放　正広; 早織田中
Original assignee: 旭化成株式会社
Priority date: 2018-01-24
Filing date: 2019-01-24
Publication date: 2019-08-01
Also published as: JPWO2019146726A1; CN111630221B; CN111630221A; JP6899453B2

Abstract

Provided is a long-fiber non-woven fabric that: is suitable for a top-sheet or back-sheet part of an absorbent article that is to be used in a sanitary material; achieves both high strength and a bulkiness that provides a cushioning softness; has surface characteristics that can be suitably utilized in sanitary materials; and has excellent processability. The present invention relates to a composite long-fiber non-woven fabric that uses, at one or both surfaces, an eccentric sheath/core long-fiber non-woven fabric that comprises eccentric sheath/core composite fibers that include at least two types of thermoplastic resin, the composite long-fiber non-woven fabric being characterized in that the eccentric sheath/core composite fibers have perfectly circular cross-sections and are configured from an elliptical high-melting-point component core part and a low-melting-point component sheath part, in that 100% of the surface of the fibers is covered by the low-melting-point component sheath parts, in that the sheath parts that cover the core parts are 100–500 nm thick at 30%–60% of the surface of the fibers, and in that the thickest portion of the sheath parts is at least 25% of the radius of the fibers. The present invention also relates to a sanitary material that uses the composite long-fiber non-woven fabric.

Description

Composite long fiber non-woven fabric using eccentric sheath-core type composite fiber on at least one surface

The present invention relates to a composite long-fiber non-woven fabric using at least one surface of an eccentric sheath-core type composite fiber composed of two or more types of thermoplastic resins, which has bulkiness and high strength with cushioning softness suitable for sanitary materials The present invention also relates to a composite long-fiber non-woven fabric having excellent surface properties required for sanitary materials such as surface smoothness and fuzz resistance.

In recent years, the spread of disposable diapers has been remarkable, and the required quality and performance have been improved. In particular, the performance required for the top sheet and the back sheet in the diaper construction is soft, and in particular, the diaper for adults may be accompanied by nursing care, and thus high strength and elongation are required. In the high quality field of diaper top sheets and back sheets in the past, staple fibers are often used, and an air through method of bonding staple fiber webs by a card method or air lay method by hot air is performed, and cushioning bulkiness Has a softness with. However, since the short fiber has almost no elongation of the fiber itself, and the strength and elongation as a non-woven fabric depend on the strength of the fiber bonding point, the bonding temperature should be raised as a means to improve the strength and the elongation. It was necessary and the texture was hard. In addition, long fibers by the spun bond method are also used for the top sheet and back sheet, but with the spun bond, high tenacity non-woven fabrics are obtained from the production method, but the fibers are arranged in the surface direction and the fibers occupying the thickness direction are It was difficult to obtain a small amount of bulkiness. That is, in the conventional long-fiber non-woven fabric, there is a problem that it is very difficult to achieve both bulkiness having cushioning softness and high strength and elongation.

On the other hand, Patent Document 1 below discloses a non-woven fabric with eccentric sheath core type fibers, but the sheath core is a perfect circle shape, there is no description of the detailed design regarding the shape of the sheath component, and the number of crimped fibers is There is little and bulkiness is inferior.

Moreover, although the following Patent Document 2 discloses a fiber spherical body using an eccentric sheath core type fiber as a material suitable for filling of a cushion or a down jacket, a sheet suitable for a top sheet or a back sheet of a sanitary material It is not suitable for formation.

Moreover, although the following patent document 3 has disclosed the short fiber nonwoven fabric which has bulkiness by the crimp expression by eccentric sheath core type | mold composite fiber, there is no description about a long fiber nonwoven fabric, and the end face of a short fiber is a nonwoven fabric The friction on the surface is high and the smooth texture is lost.

JP, 2015-165061, A JP, 2015-175074, A JP 2014-234559

In view of the above-described prior art, the problem to be solved by the present invention is to have both bulkiness and high strength having cushioning softness suitable for the top sheet and back sheet portion of the absorbent article used for sanitary materials It is an object of the present invention to provide a processable excellent long-fiber non-woven fabric having surface characteristics that can be suitably used for sanitary materials.

The present inventors diligently studied to solve the above problems, and as a result of repeating experiments, the temperature from the extruder to the spinneret regarding the low melting point component constituting the sheath and the high melting point component resin constituting the core And adjusting the residence time of the resin in the spinneret, controlling the viscosity difference of the resin in the spinneret, and designing the distribution of the resin in the spinneret to obtain a highly eccentric fiber. It was possible. The highly eccentric fiber thus obtained was discharged from the spinneret by setting the core to an elliptical shape and controlling the film thickness to an appropriate range, with the sheath covering 100% of the fiber outer circumference. In the process of drawing the yarn, the internal stress applied to the sheath in the fiber acts so as to cover the core from the periphery, and the crimp also occurs in long fibers having a fiber shape in which the sheath covers 100% of the core. It became possible to increase the number.
As the number of crimps increases, the overlapping of the yarns increases in the thickness direction of the non-woven fabric, and the fibers are adhered while maintaining the overlapping of the yarns, and furthermore, the yarn surface is covered with the 100% low melting point component. The bonding frequency is increased, and the fabric strength can be increased even with a low heat amount, and high strength, bulkiness and fuzz resistance can be obtained. Also, by making the core part elliptical so that the thickness of the thickest part of the sheath part is 25% or more of the fiber radius, the thick part of the sheath adheres and the adhesion volume of the fiber adhesion point increases, It was possible to increase the strength more. Furthermore, in the present invention, the sheath portion has a fiber structure covering 100% of the fiber surface, and the fiber cross section does not appear on the non-woven fabric surface because it is composed of long fibers, and the friction resistance is small. It has been found that the skin feels smooth and can be suitably used for hygiene applications.

That is, the present invention is as follows.
[1] A composite long-fiber non-woven fabric using an eccentric sheath-core long-fiber non-woven fabric composed of an eccentric sheath-core composite fiber containing two or more types of thermoplastic resins on at least one surface thereof, the eccentric sheath-core composite fiber Has a perfectly circular cross section, is constituted by a core of an elliptical high melting point component and a sheath which is a low melting point component, and the sheath surface which is a low melting point component covers 100% of the fiber surface A portion with a thickness of 100 to 500 nm of the sheath covering the core occupies 30 to 60% of the entire surface of the fiber, and the thickness of the thickest portion of the sheath is 25% or more of the fiber radius.
[2] The composite according to the above [1], wherein the ratio of the MFR of the high melting point component to the MI of the low melting point component (MFR of the high melting point component ÷ MI of the low melting point component) is 1.0 or more and 3.5 or less. Long fiber non-woven fabric.
[3] The composite continuous fiber non-woven fabric according to [1] or [2], wherein the side-by-side long-fiber non-woven fabric and / or the eccentric sheath-core long-fiber non-woven fabric is laminated on the eccentric sheath-core long fiber non-woven fabric .
[4] The composite according to any one of the above [1] to [3], wherein a long fiber non-woven fabric having an average fiber diameter of 0.5 to 3.0 μm is laminated on the eccentric sheath core long fiber non-woven fabric Long fiber non-woven fabric.
[5] Any one of the above [1] to [4], wherein the low melting point component thermoplastic resin constituting the sheath portion of the eccentric sheath-core type composite fiber is polyethylene having a density of 0.900 to 0.970 g / cm ³ Composite long-fiber non-woven fabric described in.
[6] The composite long-fiber non-woven fabric according to any one of the above [1] to [5], wherein the number of crimps of the eccentric sheath-core type composite fiber is 5 to 45 pieces / inch.
[7] The composite according to any one of the above [1] to [6], wherein the weight ratio of the high melting point component of the core of the eccentric sheath-core type composite fiber to the total weight of the fiber is 50 to 80%. Long fiber non-woven fabric.
[8] The composite long fiber non-woven fabric according to any one of the above [1] to [7], which has a breaking strength of 25 to 60 N / 5 cm.
[9] The composite continuous fiber non-woven fabric according to any one of the above [1] to [8], wherein the bulk density of the composite continuous fiber non-woven fabric is 0.01 to 0.07 g / cm ³ .
[10] The composite long fiber non-woven fabric according to any one of the above [1] to [9], wherein the heat seal strength of the surface on the eccentric sheath core long fiber non-woven fabric side of the composite long fiber non-woven fabric is 3 to 15 N / 5 cm.
[11] Any of the above [1] to [10], wherein the mean deviation (SMD) of the surface roughness on the eccentric sheath core type long fiber non-woven fabric side surface of the composite long fiber non-woven fabric is 1.0 to 2.4 μm or less Composite long-fiber non-woven fabric described in.
[12] The composite long fiber non-woven fabric according to any one of the above [1] to [11], wherein the fluff grade of the surface on the eccentric sheath core long fiber non-woven fabric side of the composite long fiber non-woven fabric is third grade or higher.
[13] The composite long fiber non-woven fabric according to any one of the above [1] to [12], wherein the composite long fiber non-woven fabric contains a hydrophilizing agent.
[14] A sanitary material comprising the composite long fiber non-woven fabric according to any one of the above [1] to [13].

The composite continuous fiber non-woven fabric according to the present invention is a composite continuous fiber non-woven fabric using at least one surface of an eccentric sheath-core type composite fiber composed of components utilizing two or more types of melting point differences. Since it is a non-woven fabric having excellent bulkiness and surface characteristics and high processing strength, it can be suitably used as a top sheet and a back sheet in hygiene material applications.

Hereinafter, embodiments of the present invention will be described in detail.
The composite continuous fiber non-woven fabric of the present embodiment is a composite continuous fiber non-woven fabric using at least one surface of an eccentric sheath-core type long fiber non-woven fabric composed of eccentric sheath-core type composite fibers containing two or more thermoplastic resins. The eccentric sheath-core type composite fiber has a cross section of a true circle shape, is constituted by a core portion of an elliptical high melting point component and a sheath portion which is a low melting point component, and the fiber surface is a low melting point component. A portion having a structure in which a sheath portion is 100% covered and the thickness of the sheath portion covering the core portion is 100 to 500 nm occupies 30 to 60% of the entire surface of the fiber, and the sheath portion The thickness of the thickest portion of the fiber is 25% or more of the fiber radius.

The eccentric sheath core type long fiber constituting the eccentric sheath core type long fiber nonwoven fabric is made of a combination of two or more kinds of thermoplastic resins. Examples of the thermoplastic resin include polyolefin resins such as polyethylene, polypropylene and copolymerized polypropylene, polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate and copolymer polyester, nylon-6, nylon-66, co-polymer Polyamide-based resins such as polymerized nylon, biodegradable resins such as polylactic acid, polybutylene succinate, and polyethylene succinate are used. Any combination of the above-mentioned thermoplastic resins is possible as long as the desired effect is not impaired, and a combination of thermoplastic resins having a melting point difference is preferable in terms of bonding of the fibers. Among them, in terms of texture, it is preferable to use a combination of polyolefin resins. For example, composite fibers combined from resins such as polyethylene, polypropylene and copolymers of those monomers with other α-olefins can be mentioned. Other α-olefins are those having 3 to 10 carbon atoms, and specific examples thereof include propylene, 1-butene, 1-pentene, 1-hexane, 4-methyl-1-pentene, 1-octene and the like Be

Since the fiber shape of the eccentric sheath core type long fiber constituting the eccentric sheath core type long fiber nonwoven fabric is literally an eccentric sheath core type, crimped yarn can be easily obtained. The core is elliptical and forms a thin film in the range of 30 to 60% of the surface layer of the fiber, the thin film has a thickness of 100 nm to 500 nm, and the thickest part of the sheath is 25% or more of the fiber radius By forming the occupied film, fibers having high eccentricity can be obtained. From the viewpoint of crimpability, the thickness of the sheath thin film is 100 nm to 500 nm, preferably 100 nm to 400 nm, and more preferably 100 nm to 300 nm. In addition, similarly, from the viewpoint of crimpability, the ratio of the thin film to the surface layer of the fiber is 30 to 60%, more preferably 30 to 50%, and still more preferably 30 to 40%. The thickest part of the sheath part is 25% or more, preferably 30% or more, more preferably 35% or more of the fiber radius. The core part is 100% covered with the sheath part, which results from the adhesion between the sheath parts, and high strength and fluff suppression can be obtained.

The cross-sectional shape of the eccentric sheath core long fiber constituting the eccentric sheath core long fiber non-woven fabric is a true circle shape.
In the present specification, the term "perfect circular shape" means that the ratio of the length of the longest diameter of the fiber cross section to the length of the shortest diameter is 0.8 to 1.0, preferably It is 0.9 to 1.0, more preferably 0.95 to 1.0. If the fiber cross section has a perfect circular shape, stable spinning is possible, and furthermore, it is possible to obtain a non-woven fabric having a good feeling that does not feel trapped when touching the fiber.

In order to control the shape of the core and obtain high eccentricity, it is very important to control the difference in viscosity characteristics between the high melting point component constituting the core and the low melting point component constituting the sheath. However, when the core portion and the sheath portion have too much characteristic difference, the sheath portion does not cover the entire circumference of the fiber, or the eccentricity is low and the number of crimps is small.
An appropriate range of the viscosity characteristic difference (MFR / MI ratio) of the high melting point component and the low melting point component is 1.0 or more and 3.5 or less as a value obtained by dividing the MFR of the high melting point component by the MI of the low melting point component. Is preferred. By setting the MFR / MI ratio to 1.0 or more, the core can be formed into an elliptical shape, and as the MFR / MI ratio is larger, the viscosity difference becomes larger and the eccentricity becomes higher. The lower limit value is more preferably 1.7 or more, still more preferably 2.0 or more, and most preferably 2.1 or more because the property is obtained. On the other hand, by setting the MFR / MI ratio to 3.5 or less, the sheath can cover the entire circumference of the fiber, so 3.5 or less is preferable from the viewpoint of the adhesion between the fibers.

When the eccentric sheath core long fibers constituting the eccentric sheath core long fiber nonwoven fabric are formed of two types of thermoplastic resins, it is preferable that the high melting point component is polypropylene and the low melting point component is polyethylene. The weight ratio of the high melting point component to the whole fiber is preferably 50 to 80%, more preferably 60 to 70%, and still more preferably 65 to 70%. By using polypropylene as the high melting point component, it is high in strength and difficult to be broken at the time of use, and is excellent in dimensional stability at the time of production of the sanitary material. By using polyethylene as the low melting point component, the sheath part is attributable to adhesion, so that high strength and fluff suppression can be obtained.

The high melting point component polypropylene in the case of forming with the above two types of thermoplastic resins may be a polymer synthesized by a general Ziegler Natta catalyst, or a polymer synthesized by a single site active catalyst represented by a metallocene, etc. Also, ethylene random copolymer polypropylene may be used. These may be used alone or in combination of two or more. In particular, homopolypropylene is preferred as the main component in terms of texture, strength and dimensional stability.
The lower limit of the MFR of polypropylene is preferably 20 g / 10 min or more, more preferably 30 g / 10 min or more, still more preferably 40 g / 10 min or more, and most preferably 53 g / 10 min or more. The upper limit of the MFR of polypropylene is preferably 85 g / 10 min or less, more preferably 70 g / 10 min or less, and still more preferably 60 g / 10 min or less. MFR was measured according to JIS-K7210 “Test method of melt mass flow rate (MFR) and melt volume flow rate (MVR) of plastic-thermoplastics”, test temperature 230 ° C., test load 2.16 kg. .

The polyethylene resin of the low melting point component in the case of forming with the two types of thermoplastic resins can be suitably used as a hygienic material from the viewpoint that the adhesive strength after bonding of the fibers is strong and the texture as a non-woven fabric is good. Also, polyethylene may be a polymer synthesized by a general Ziegler-Natta catalyst, or a polymer synthesized by a single site activated catalyst represented by a metallocene. As polyethylene, high density polyethylene, linear low density polyethylene, low density polyethylene can be used, and the density is preferably 0.90 to 0.97 g / cm ³ , more preferably 0.91 to It is 0.96 g / cm ³ .

The lower limit of MI of polyethylene is preferably 10 g / 10 min or more, more preferably 15 g / 10 min or more. On the other hand, the upper limit of MI of polyethylene is preferably 50 g / 10 min or less, more preferably 45 g / 10 min or less. MI was measured according to JIS-K7210 “Test method of melt mass flow rate (MFR) and melt volume flow rate (MVR) of plastic-thermoplastics”, test temperature 190 ° C., test load 2.16 kg. .

In order to obtain a desired sheath core shape in the eccentric sheath core long fiber constituting the eccentric sheath core long fiber non-woven fabric, there is a difference between the viscosity of the low melting point component and the high melting point component when discharged from the spinning port Is important and control of the spinning temperature is necessary. When polyethylene is selected as the low melting point component and polypropylene is selected as the high melting point component, the spinning temperature is preferably 200 ° C. or more and 260 ° C. or less, more preferably 230 ° C. or more and 250 ° C. to obtain a desired fiber cross-sectional shape. It is less than ° C. If the temperature is less than 200 ° C., the viscosity of both polypropylene and polyethylene becomes high, and the difference in viscosity becomes small, so a desired fiber shape can not be obtained. If the temperature exceeds 260 ° C., the flowability of the polyethylene which is the sheath becomes high, and after it is discharged from the spinning nozzle, the thickness of the sheath becomes large and the desired fiber shape can not be obtained.

The eccentric sheath core type long fibers constituting the eccentric sheath core type long fiber non-woven fabric preferably have a helical crimp in order to maintain the texture and bulkiness of the non-woven fabric. The number of crimps of the fiber is preferably 5 to 45 / inch, and more preferably 10 to 40 / inch. If the number of crimps is less than 5 pieces / inch, the bulk of the obtained nonwoven fabric is insufficient, while if it exceeds 45 pieces / inch, the appearance of the obtained nonwoven fabric is impaired due to the uneven fiber dispersion of the obtained nonwoven fabric.

The eccentric sheath-cored long-fiber non-woven fabric is preferably a composite long-fiber non-woven web formed by a spunbond method from the viewpoint of strength and productivity. Such composite long fibers are produced, for example, by melt extruding different thermoplastic resins from two or more different extruders, and as a yarn in a state in which two or more types of thermoplastic resins are compounded from a spinneret having a large number of spinning holes. It is discharged. Next, cold air controlled at 5 ° C. to 20 ° C. is applied to the discharged yarn, and it is pulled while being cooled. The yarn exiting from the pulling device is deposited on a conveyer and conveyed as a nonwoven web. The nonwoven web being transported may be laminated to form a multilayer laminated nonwoven web.

As a joining means in the case of joining the nonwoven web comprised with a thermoplastic conjugate fiber and making it into a nonwoven fabric, it will not be limited especially if it is a method of heating more than the temperature which the intersection of fibers melts and adheres . As a heating method, various heating methods such as a hot air circulation type, a hot air penetration type, an infrared heater type, a method of blowing hot air to both surfaces of a non-woven fabric, a method of introducing into a heating gas, and the like are used. From the viewpoint of obtaining more fiber bonding points at the intersections of the fibers and increasing the breaking strength of the non-woven fabric, heating with hot air is preferable, and in particular, a hot air penetrating type is preferable.

Among the combined thermoplastic resins, the temperature of the hot air is preferably adjusted to a temperature suitable for the thermoplastic resin having a low melting point and contributing to bonding. As the production speed increases, it is necessary to raise the temperature to secure the amount of heat that contributes to adhesion, and the appropriate temperature is adjusted according to the production conditions. For example, when the thermoplastic resin is polyethylene, polyethylene is The temperature is 125 to 155 ° C., preferably 130 to 155 ° C., more preferably 135 ° C. to 150 ° C. for melting and bonding. If the bonding temperature is in this range, bonding of the fibers is developed at the intersection of the fibers without impairing the texture, and it becomes possible to develop the strength as a non-woven fabric.

The velocity of the hot air is preferably 0.5 m / sec to 3.0 m / sec, more preferably 0.7 m / sec to 2.5 m / sec, still more preferably 0.7 m / sec to 2.0 m / sec It is. If the wind speed of the hot air is in this range, adhesion of the fibers is developed at the intersection of the fibers without impairing the texture, and the strength as the non-woven fabric can be developed.

In this embodiment, the non-woven web before bonding or after bonding of the non-woven fabric may be subjected to heat bonding by embossing. It is preferable from the viewpoint of productivity to process embossing through a pair of rolls of a combination of a metal embossing roll and a metal flat roll. The embossed area ratio is preferably 5 to 30%, more preferably 5 to 20%, and still more preferably 6 to 15%, from the viewpoint of shape retention of the nonwoven web and the strength of the finally obtained nonwoven fabric. In addition, the deeper the emboss depth, the softer the non-woven fabric can be obtained, preferably 0.5 to 2.0 mm, more preferably 0.7 to 1.5 mm. The emboss shape is not particularly limited, but is preferably circular, oval, diamond, or rectangular, in order to obtain a non-woven fabric having softness and appropriate strength and elongation suitable for use in sanitary materials. Can be selected as appropriate.

The composite continuous fiber non-woven fabric of the present embodiment may be obtained by laminating the eccentric sheath-core long-fiber non-woven fabric with a side-by-side long-fiber non-woven fabric and / or an eccentric sheath-core long-fiber non-woven fabric. The side-by-side type long fiber non-woven fabric has high crimpability of fibers by separating the center of gravity position of the two components and can obtain non-woven fabric with high bulkiness, but the ratio of the fiber surface of low melting point component decreases. Fuzziness and strength may be reduced. By combining the layers in the layer structure, it is possible to obtain a composite long fiber non-woven fabric having a part with good side-by-side type and eccentric sheath core type. Furthermore, when the composite continuous fiber nonwoven fabric of the present embodiment uses the nonwoven fabric as a sanitary material and the surface in contact with the skin is the surface layer, using the eccentric sheath core type composite long fiber as the surface layer impairs the texture. Absent. In addition, an eccentric sheath-core type composite long fiber non-woven fabric having a structure difference in which the number of crimps and the fineness, and the weight ratio of the high melting point and the low melting point component are different may be laminated on the eccentric sheath-core type composite long fiber non-woven fabric.

The average single fiber fineness of the eccentric sheath-core type composite long fiber is preferably 1.0 dtex or more and 3.5 dtex or less, more preferably 1.2 dtex or more and 3.3 dtex or less, still more preferably 1.5 dtex or more and 3.0 dtex or less It is. From the viewpoint of spinning stability, the average single yarn fineness is preferably 1.0 dtex or more, and from the viewpoint of the feel of the non-woven fabric used for sanitary materials, it is preferably 3.5 dtex or less.

Basis weight of the composite long fiber nonwoven fabric of the present embodiment is preferably 10 g / ^{m 2} or more 50 g / ^{m 2} or less, more preferably 10 g / ^{m 2} or more 40 g / ^{m 2} or less, more preferably 12 g / ^{m 2} or more 30 g / m ² or less. If the weight per unit area is 10 g / m ² or more, the nonwoven fabric used for the sanitary material satisfies the strength, while if 50 g / m ² or less, the softness of the nonwoven fabric used for the sanitary material is satisfied, Do not give a thick impression.

In this embodiment, a long fiber non-woven fabric having an average fiber diameter of 0.5 μm to 3.0 μm may be laminated on the eccentric sheath-core type composite long fiber non-woven fabric. By laminating long fibers with an average fiber diameter of 0.5 μm to 3.0 μm, the coverage of the non-woven fabric can be improved, the dispersion unevenness of appearance is improved, and the hot melt agent escapes when used for sanitary materials Or, it can be suitably used to suppress the loss of a highly absorbent resin (SAP) when used as a top sheet. There is no particular limitation on the method for obtaining the fiber having an average fiber diameter of 0.5 μm to 3.0 μm, but the melt-blown method is preferable from the combination of the productivity and the spun bond method. The range of the fiber diameter is preferably 0.5 μm to 3.0 μm, more preferably 0.7 μm to 2.5 μm, and still more preferably 1.0 μm to 2.3 μm.

The bulk density of the composite continuous fiber non-woven fabric of the present embodiment is preferably in the range of 0.01 g / cm ^{3 to} 0.07 g / cm ³ . The bulk density is preferably 0.01 g / cm ³ or more from the viewpoint of strength, and is preferably 0.07 g / cm ³ or less from the viewpoint of texture.

The breaking strength of the composite continuous fiber non-woven fabric of the present embodiment is preferably 25 N / 5 cm to 60 N / 5 cm, more preferably 30 N / 5 cm to 50 N / 5 cm, and still more preferably 35 N / 5 cm to 45 N / 5 cm. is there. When the breaking strength is 25 N / 5 cm or more, when used for sanitary materials, it does not stretch or break when it is put on at the time of wearing, and if it is 60 N / 5 cm or less, the texture is soft and it is used for sanitary materials It can be used suitably.

The heat seal strength of the composite long fiber non-woven fabric of the present embodiment is preferably in the range of 3N / 5 cm to 15 N / 5 cm, more preferably 5 N / 5 cm to 12 N / 5 cm, still more preferably 7 N / 5 cm to 10 N / 5 cm. . If the heat seal strength is 3 N / 5 cm or more, the heat seal portion can be used without peeling or tearing when used as a sanitary material application, and if 15 N / 5 cm or less, the heat seal portion is over-welded. It does not form a film, has a soft texture, and can be suitably used for sanitary materials.

The mean deviation (SMD) of the surface roughness of the surface of the eccentric sheath core type long fiber non-woven fabric side of the composite long fiber non-woven fabric of this embodiment is preferably 1.0 μm or more and 2.4 μm or less, and 1.4 μm or more and 2.2 μm or less More preferably, it is more preferably 1.6 μm or more and 2.0 or less. By setting the average deviation of the surface roughness to 2.4 μm or less, there is less irritation to the skin surface and the texture is improved, so it can be suitably used in the application of a guarding material, while it is 1.0 μm or more By giving a moderate uneven feeling, a soft texture with cushioning properties can be obtained.

The fluff grade of the surface on the eccentric sheath core type long fiber non-woven fabric side of the composite long fiber non-woven fabric of the present embodiment is preferably 3 or more, more preferably 4 or more, and still more preferably 5 or more. If the fluff grade is grade 3 or higher, the fiber-bonded portion of the non-woven fabric surface is not easily peeled off even when rubbed with the skin, fluffing of the fiber surface is suppressed, and sticking to the skin and fingertips can be reduced. It can be obtained and can be suitably used in a guarding material application.

The composite long-fiber non-woven fabric of the present embodiment may contain a hydrophilizing agent. As a hydrophilizing agent to be used, in consideration of safety to the human body, safety in the process, etc., nonionic surfactants added with ethylene oxide such as higher alcohols, higher fatty acids, alkylphenols, alkyl phosphate salts And anionic surfactants such as alkyl sulfates, etc., which may be used alone or as a mixture.

As a method of incorporating a hydrophilizing agent, an existing method such as a dipping method, a spraying method, a coating (kiss coater, gravure coater) method or the like can be usually employed using a diluted hydrophilizing agent, and hydrophilicity mixed in advance if necessary Preferably, the agent is diluted with a solvent such as water and then applied.

If the hydrophilizing agent is diluted with a solvent such as water and then applied, a drying step may be required. As a drying method in that case, a known method using convection heat transfer, conduction heat transfer, radiation heat transfer, etc. can be adopted, and drying by hot air or infrared rays, a drying method by thermal contact, etc. can be used.

Although the adhesion amount of the hydrophilizing agent varies depending on the required performance, it is usually preferably in the range of 0.05% by weight or more and 1.00% by weight or less, more preferably 0.15% by weight or more based on the fiber. .8% by weight or less, more preferably 0.2% by weight or more and 0.6% by weight or less. When the adhesion amount is in this range, the hydrophilic performance as a top sheet of the sanitary material is satisfied, and the processing suitability is also good.

The composite long-fiber non-woven fabric of the present embodiment can be suitably used for the production of a sanitary material because it has a bulkiness having a cushioning softness and a high strength and elongation. Hygiene materials include disposable diapers, sanitary napkins, incontinence pads and the like, and the composite long-fiber non-woven fabric of the present embodiment can be suitably used particularly for the top sheet on the surface and the back sheet on the outside.

In addition, applications of the composite long fiber non-woven fabric of the present embodiment are not limited to the above applications, and, for example, masks, cairos, tape bases, waterproof sheet bases, patched medicine bases, first aid base, packaging materials, wipes It may be used for products, medical gowns, bandages, clothing, skin care sheets and the like.

Hereinafter, the present invention will be specifically described by way of examples and comparative examples, but the present invention is not limited to only the following examples. From the characteristics of the fibers and non-woven fabric to be produced, the temperature in the bonding step, the hot wind speed and the like are appropriately changed depending on the weight of the fabric to be produced and the line speed. In addition, the evaluation method of each characteristic is as follows, and the obtained physical property etc. are shown to the following Tables 1 and 2. In this specification, the production line direction (flow direction of fibers) of the composite long fiber nonwoven fabric of the present embodiment is referred to as MD direction, and the width direction orthogonal to the flow direction of fibers is referred to as CD direction.

1. Average single yarn fineness (dtex), average fiber diameter (μm)
Except for 10 cm at both ends of the manufactured non-woven fabric, the test piece of 1 cm square is sampled in approximately 5 equal parts in the CD direction, and the diameter of fibers is measured at 20 points each with a Keyence microscope VHX-700F. The fineness and the fiber diameter were calculated from the values.

2. Basis weight (g / m ² )
According to JIS-L 1906, five test pieces of 20 cm in the MD direction and 5 cm in the CD direction were arbitrarily collected to measure the mass, and the average value was converted into the weight per unit area.

3. Breaking strength (N / 5 cm)
According to JIS L-1906, except for 10 cm on both ends of manufactured non-woven fabric, 5 samples of 5 cm in CD direction and 20 cm in MD direction are cut out so as to be uniform in CD direction, grip distance 10 cm, tensile speed with tensile tester It measured at 30 cm / min. The samples at five points in the MD direction were measured, and the measured values were averaged to calculate the breaking strength.

4. Bulk density (g / cm ³ )
The average thickness was calculated by measuring 20 points with a peacock-type thickness gauge (5 gf / 4 cm ² ) so as to make the CD direction uniform except for both ends 10 cm of the manufactured non-woven fabric. The following formula:
Bulk density (g / cm ³ ) = area weight (g / m ² ) / thickness (mm) / 1000
The bulk density was calculated by

5. Sheath thickness (nm), fiber surface occupancy (%)
The test piece of 5 mm in the CD direction and 20 mm in the MD direction was sampled by dividing into approximately 5 equal parts in the CD direction except 10 cm of both ends of the manufactured non-woven fabric, and fibers were cut perpendicular to the fiber length direction. Set on the sample stand so that the cut end face can be observed, observe the fiber cross section with a microscope VHX-700F manufactured by Keyence Corporation, draw a tangent at the interface between the high melting point component of the core and the low melting point component of the sheath When the perpendicular is drawn to the tangent, the distance from the point where the perpendicular not passing through the core intersects the fiber surface to the contact point of the boundary surface is measured as the thickness of the sheath, and the thickness of the thickest part is 100 The proportion of the range of ̃500 nm was measured. Twenty fibers were measured at a time and calculated from the average value.

6. Heat seal strength (N / 5 cm)
A sample of 3 cm in the CD direction and 20 cm in the MD direction is cut out so as to be uniform in the CD direction except 10 cm at both ends of the manufactured nonwoven fabric, and folded so as to overlap both ends of the nonwoven fabric. The creased end was pressed for 1 second with a force of 70 N / 1 cm with a 3 cm × 10 cm hot plate heated at 125 ° C. for bonding. The breaking strength was calculated by averaging measured values of samples at five points in the MD direction with a tension tester at a grip distance of 10 cm and a tensile speed of 30 cm / min so as to split the non-bonded end up and down. .

7. Average deviation of surface roughness (SMD) (μm)
Three samples of 6 cm × 8 cm were prepared from arbitrary places of the manufactured non-woven fabric. A sample is mounted on the measuring stand of Friction Feel Tester (KES-SE) manufactured by Kato Tech Co., Ltd., and a load of 25 g / cm ^{2 is} measured using the sample and a standard friction terminal (10 mm square metal wire terminal) of the friction feel tester. The average deviation (SMD) of the surface roughness was measured by the above, and the average value in the MD direction of the sample was calculated.

8. Fuzz grade (class)
Take a 25 mm x 300 mm test piece in the CD direction, use the Japan Society for the Promotion of Science Fastness Tester, load the friction element 150 g, use the same cloth on the friction element side, and operate 100 times, It was judged by the following evaluation criteria:
5.0 grade: no fuzz grade 4.0: about 1 or 2 fibers, or a small floss at a single location, fuzziness grade 3.0: a clear floss begins to be produced, Or, a plurality of small pill is observed. Grade 2.0: The thinner the specimen, the more the fibers are peeled off. Grade 1.0: The larger the breakage of the specimen, the fibers are scraped off.

9. Number of crimps (pieces / inch)
Except for 10 cm at both ends of the non-woven fabric, a test piece of 5 cm square is sampled in approximately 5 equal parts in the CD direction, and 2.54 cm (1 inch) per 2.54 cm (one inch) with no load applied to fibers with a Keyence Microscope VH-Z450. The number of crimps was measured, and the number of crimps was calculated from the average value.

Example 1
A polypropylene (hereinafter also referred to as PP) resin with an MFR of 55 g / 10 min (measured according to JIS-K 7210 at a temperature of 230 ° C. and a load of 2.16 kg) as the high melting point component, and an MI of 26 g / 10 min (JIS-K A high-density polyethylene (hereinafter also referred to as HDPE) resin with a temperature of 190 ° C and a load of 2.16 kg according to K7210 as the low melting point component, and the ratio of the high melting point component to the low melting point component is 67/33. Were extruded at a spinning temperature of 230 ° C. by a spunbond method, and captured on a moving collection surface to prepare an eccentric sheath-cored long-fiber non-woven web having an average single fiber fineness of 2.9 dtex.
Then, the obtained web was bonded to each other with a hot air temperature of 140 ° C. and a hot air velocity of 1.0 m / sec to obtain a composite long-fiber non-woven fabric with a crimp number of 20 / inch at a basis weight of 25 g / m ² .

Example 2
A composite long-fiber non-woven fabric was obtained in the same manner as in Example 1, except that the ratio of the high melting point component to the low melting point component was 75/25.

[Example 3]
A composite long-fiber non-woven fabric was obtained in the same manner as in Example 1 except that the ratio of the high melting point component to the low melting point component was 80/20.

Example 4
A composite long-fiber non-woven fabric was obtained in the same manner as in Example 1 except that the HDPE resin having a MI of 23 g / 10 min was used as the low melting point component.

[Example 5]
A composite long-fiber non-woven fabric was obtained in the same manner as in Example 1 except that a PP resin having a MFR of 40 g / 10 min was used as the high melting point component and an HDPE resin having an MI of 19 g / 10 min was used as the low melting point component.

[Example 6]
A composite long-fiber non-woven fabric was obtained in the same manner as in Example 1 except that a PP resin having MFR of 33 g / 10 min was used as the high melting point component and an HDPE resin having MI of 19 g / 10 min was used as the low melting point component.

[Example 7]
Example 1 and Example 1 except that the PP resin having MFR of 33 g / 10 min. Is a high melting point component and the linear low density polyethylene (hereinafter referred to as LLDPE) resin having an MI of 17 g / 10 min. In the same manner, a composite long fiber non-woven fabric was obtained.

[Example 8]
A composite long-fiber non-woven fabric was obtained in the same manner as in Example 1 except that LLDPE resin having a MI of 17 g / 10 min was used as the low melting point component.

[Example 9]
A composite long-fiber non-woven fabric in the same manner as in Example 1 except that the PP resin having MFR of 33 g / 10 min is used as the high melting point component and the low density polyethylene (LDPE) resin having MI of 31 g / 10 min is used as the low melting point component. I got

[Example 10]
A composite long-fiber non-woven fabric was obtained in the same manner as in Example 1 except that the LDPE resin having a MI of 31 g / 10 min was used as the low melting point component.

[Example 11]
The composite long fiber non-woven fabric of the same condition was further laminated on the composite long fiber non-woven fabric obtained in Example 1, and the line speed was adjusted so that the fabric weight was 25 g / m ² to obtain a composite long fiber non-woven fabric.

[Example 12]
A side-by-side type composite long fiber having a MFR of 55 g / 10 min as a PP resin as a high melting point component, an MI of 26 g / 10 min as a low melting point component, and a 50/50 ratio of a high melting point component to a low melting point component The composite long fiber nonwoven fabric prepared by the same method as in Example 1 was laminated on the composite long fiber nonwoven fabric obtained in Example 1, and the line speed was adjusted to obtain a composite long fiber nonwoven fabric with a fabric weight of 25 g / m ² .

[Example 13]
A single-component PP resin with an MFR of 1000 g / 10 min is extruded at a spinning temperature of 220 ° C. by a meltblown method at a single hole discharge rate of 0.1 g / m ² , and this filament group is pulled at an HA temperature of 300 ° C. A web adjusted to a diameter of 2.0 μm is sprayed onto the eccentric sheath-cored long-fiber non-woven web obtained in Example 1 and laminated, and the eccentric sheath-cored long-fiber non-woven fabric obtained in Example 1 on this laminated web The web was laminated and the line speed was adjusted to obtain a composite long fiber non-woven fabric having a basis weight of 15 g / m ² .

Example 14
The eccentric sheath core type long fiber nonwoven fabric obtained in the same manner as in Example 1 is laminated on the laminate of the eccentric sheath core type long fiber nonwoven fabric obtained in Example 12 and the side-by-side type composite long fiber nonwoven fabric, and the line speed is adjusted. The composite long fiber nonwoven fabric of 20 g / m ² in basis weight was obtained.

[Example 15]
A laminate of the eccentric sheath core long fiber nonwoven web and the side-by-side long fiber nonwoven web obtained in Example 12 is laminated on the eccentric sheath core long fiber nonwoven web obtained in Example 1, and the line speed is It adjusted and obtained the composite long fiber nonwoven fabric of 20 g / m < ² > of fabric weight.

[Example 16]
An eccentric sheath-cored long-fiber non-woven web is prepared in the same manner as in Example 1, and then the obtained non-woven fabric is applied with a polyether hydrophilizing agent by a spraying method, and then heated at 120 ° C for 1.0 seconds. It dried and obtained the composite long-fiber nonwoven fabric used as the agent concentration adhesion amount 0.5 weight%. The obtained non-woven fabric was a non-woven fabric of the same performance as Example 1 with satisfactory performance as a top sheet of a diaper.

[Example 17]
A composite long-fiber non-woven fabric was obtained in the same manner as in Example 16, except that the amount of the agent concentration of the polyether-based hydrophilizing agent was 0.25% by weight. The obtained non-woven fabric had satisfactory performance as a diaper top sheet, and was a non-woven fabric of the same performance as Example 1.

Comparative Example 1
A composite long-fiber non-woven fabric was obtained in the same manner as in Example 1 except that the HDPE resin having a MI of 70 g / 10 min was used as the low melting point component.

Comparative Example 2
A composite long-fiber non-woven fabric was obtained in the same manner as in Example 1 except that a PP resin having a MFR of 29 g / 10 min was used as the high melting point component and an HDPE resin having an MI of 32 g / 10 min was used as the low melting point component.

Comparative Example 3
A composite long-fiber non-woven fabric was obtained in the same manner as in Example 1 except that L LDPE resin having a MI of 120 g / 10 min was used as the low melting point component.

Comparative Example 4
A composite long fiber non-woven fabric was obtained in the same manner as Example 1, except that the ratio of the high melting point component to the low melting point component was 90/10.

Comparative Example 5
A composite long-fiber non-woven fabric was obtained in the same manner as Example 1, except that the ratio of the high melting point component to the low melting point component was 20/80.

Comparative Example 6
Composite long fiber in the same manner as Example 1, except that the HDPE resin having a MI of 32 g / 10 min is used as the low melting point component and the ratio of the high melting point component to the low melting point component is 50/50. I got a non-woven fabric.

Comparative Example 7
A composite long-fiber non-woven fabric was obtained in the same manner as in Comparative Example 6 except that the low melting point component MI was 48 g / 10 min.

Comparative Example 8
The composite length is the same as in Example 1, except that the low melting point component MI is 48 g / 10 min HDPE resin and the ratio of the high melting point component to the low melting point component is 67/33. A fiber non-woven fabric was obtained.

Comparative Example 9
Except that the eccentric sheath core type composite long fiber non-woven fabric obtained in Example 1 was laminated on the side-by-side type composite long fiber non-woven fabric obtained in Comparative Example 7 and further the side-by-side type composite long fiber non-woven fabric obtained in Comparative Example 7 was laminated. The line speed was adjusted in the same manner as in Example 1 to obtain a composite long-fiber non-woven fabric having a basis weight of 25 g / m ² .

Claims

A composite long fiber non-woven fabric using an eccentric sheath core long fiber non-woven fabric composed of an eccentric sheath core type composite fiber containing two or more kinds of thermoplastic resins on at least one surface, said eccentric sheath core type composite fiber being true A structure having a circular cross section, a core of an elliptical high melting point component, and a sheath of a low melting point component, and a sheath of the low melting point component covering the fiber surface 100% The portion having a thickness of 100 to 500 nm of the sheath covering the core occupies 30 to 60% of the entire surface of the fiber, and the thickness of the thickest portion of the sheath represents the fiber radius 25% or more of the composite long-fiber non-woven fabric characterized in that
The composite long-fiber non-woven fabric according to claim 1, wherein a ratio of MFR of the high melting point component to MI of the low melting point component (MFR of high melting point componentMIMI of low melting point component) is 1.0 or more and 3.5 or less.
The composite continuous fiber non-woven fabric according to claim 1 or 2, wherein the side-by-side long-fiber non-woven fabric and / or the eccentric sheath-core long-fiber non-woven fabric is laminated on the eccentric sheath-core long fiber non-woven fabric.
The composite long fiber non-woven fabric according to any one of claims 1 to 3, which is formed by laminating a long fiber non-woven fabric having an average fiber diameter of 0.5 to 3.0 μm on the eccentric sheath core long fiber non-woven fabric.
The thermoplastic resin of the low melting point component which comprises the sheath part of the said eccentric sheath core type | mold composite fiber is a polyethylene of the density 0.900-0.970 g / cm < 3 > of any one of Claim 1 to 4 Composite long fiber non-woven fabric.
The composite long-fiber non-woven fabric according to any one of claims 1 to 5, wherein the number of crimps of the eccentric sheath-cored composite fiber is 5 to 45 / inch.
The composite long fiber nonwoven fabric according to any one of claims 1 to 6, wherein a weight ratio of the high melting point component of the core of the eccentric sheath-core type composite fiber to the total weight of the fiber is 50 to 80%.
The composite continuous fiber nonwoven fabric according to any one of claims 1 to 7, wherein a breaking strength of the composite continuous fiber nonwoven fabric is 25 to 60 N / 5 cm.
The bulk density of the composite long fiber nonwoven fabric is 0.01 ~ 0.07g / cm 3, composite long fiber nonwoven fabric according to any one of claims 1-8.
The composite long fiber non-woven fabric according to any one of claims 1 to 9, wherein the heat seal strength of the surface on the eccentric sheath core long fiber non-woven fabric side of the composite long fiber non-woven fabric is 3 to 15 N / 5 cm.
The average deviation (SMD) of the surface roughness of the eccentric sheath core type long fiber non-woven fabric side surface of the composite long fiber non-woven fabric is 1.0 to 2.4 μm or less according to any one of claims 1 to 10. Composite long fiber non-woven fabric.
The composite long fiber non-woven fabric according to any one of claims 1 to 11, wherein the fluff grade of the surface on the eccentric sheath core long fiber non-woven fabric side of the composite long fiber non-woven fabric is third grade or higher.
The composite long fiber non-woven fabric according to any one of claims 1 to 12, wherein the composite long fiber non-woven fabric contains a hydrophilizing agent.
A hygienic material comprising the composite long fiber nonwoven fabric according to any one of claims 1 to 13.