WO2018079635A1

WO2018079635A1 - Spunbond nonwoven fabric and method for manufacturing same

Info

Publication number: WO2018079635A1
Application number: PCT/JP2017/038602
Authority: WO
Inventors: 仁溝上; 松浦　博幸; 拓史小林
Original assignee: 東レ株式会社
Priority date: 2016-10-27
Filing date: 2017-10-26
Publication date: 2018-05-03
Also published as: JP7070404B2; TW201819705A; KR20190066019A; KR102242725B1; JPWO2018079635A1

Abstract

Provided is a spunbond nonwoven fabric having superior transverse tensile strength and excellent texture and quality. This spunbond nonwoven fabric comprises thermoplastic continuous filaments and is formed by partial thermocompression bonding, said spunbond nonwoven fabric being characterized in that the peak for fiber orientation distribution for the filaments in the vertical direction of the nonwoven fabric is at 10 – 50° and the vertical/transverse ratio for tensile strength of the nonwoven fabric is 1.3 – 1.8.

Description

Spunbond nonwoven fabric and method for producing the same

The present invention relates to a spunbonded nonwoven fabric suitable for use as a house wrap material.

In recent construction of wooden houses and the like, a ventilation layer method is widely used in which a ventilation layer is provided between an outer wall material and a heat insulating material, and moisture that has entered the wall body is released to the outside through the ventilation layer. This ventilation layer construction method is a spunbond nonwoven fabric as a house wrap material that is a moisture permeable waterproof sheet that has both waterproof properties to prevent rainwater from entering outside the building and moisture permeability that allows moisture generated inside the wall to escape to the outside. Is used.

As the moisture permeable waterproof sheet, a house wrap material in which a polyethylene perforated film and a nonwoven fabric are laminated and integrated is widely used. The strength and the like of this sheet are regulated by Japanese Industrial Standards JIS A6111: 2004. is there. According to the JIS standard, the tensile strength of both vertical and horizontal is defined to be 100 N / 5 cm or more. To satisfy this standard value, the tensile strength of the spunbonded nonwoven fabric is important. Generally, since the vertical tensile strength is stronger than the horizontal tensile strength, an improvement in the horizontal tensile strength is particularly required.

House wrap material is fixed and applied to the ground with spelling needles (also known as tucker needles and staples), and has excellent long-term durability and weather resistance under high and low temperature conditions, and can be easily torn during construction. Not mechanical strength is required.

Conventionally, as a non-woven fabric used for such a house wrap material, a house wrap material having one surface smoothness and a strong tear strength in the vertical direction has been proposed in order to improve the adhesiveness to the waterproof tape (Patent Document 1). reference.).

Japanese Unexamined Patent Publication No. 2014-40677

However, in the invention described in this patent document, when the angle of the nozzle that swings with respect to the traveling direction of the web (longitudinal direction of the nonwoven fabric) is set to 60 degrees, for example, the orientation tends to be horizontal, and the tensile strength in the horizontal direction is increased. Make it high. As a result, the present inventors have a problem that the web on the moving collection surface is crawled, and there is a problem that the nonwoven fabric for house wrap material does not have a stable texture or quality. I found it.

Therefore, an object of the present invention is to provide a spunbonded nonwoven fabric having excellent horizontal tensile strength and good formation and quality, and a method for producing the same.

The spunbonded nonwoven fabric of the present invention is a spunbonded nonwoven fabric partially formed by thermocompression bonding composed of thermoplastic continuous filaments, and the fiber orientation degree distribution peak of the filament with respect to the vertical direction of the nonwoven fabric is 10 to 50 The spunbonded nonwoven fabric is characterized in that the nonwoven fabric has a tensile strength warp / width ratio of 1.3 to 1.8.

According to a preferred embodiment of the spunbonded nonwoven fabric of the present invention, the fiber ratio with a fiber orientation of 10 to 50 degrees is 60 to 80%.

According to a preferred embodiment of the spunbonded nonwoven fabric of the present invention, the horizontal tensile strength per unit weight is 2.2 N / 5 cm / (g / m ² ) or more.

According to a preferred embodiment of the spunbond nonwoven fabric of the present invention, the thermoplastic continuous filament is a composite filament in which a low melting point polymer having a melting point lower than the melting point of the high melting point polymer is disposed around the high melting point polymer. is there.

According to a preferred embodiment of the spunbonded nonwoven fabric of the present invention, it has a partial thermocompression bonding portion with an area ratio of 8 to 30%.

According to a preferred aspect of the spunbonded nonwoven fabric of the present invention, the spunbonded nonwoven fabric can be used as a house wrap material.

The method for producing a spunbonded nonwoven fabric according to the present invention is a method for producing a spunbonded nonwoven fabric characterized by sequentially performing the following (a) to (d).
(A) Step of obtaining a thermoplastic continuous filament by drawing and stretching the thermoplastic polymer from a spinneret and then drawing and stretching it with an air soccer (b) The obtained filament is 5 to 25 with respect to the web traveling direction. The step of swinging the spray nozzle directed in the direction of degrees within a range of ± 10 to ± 25 degrees to open the filament (c) depositing the opened filament on a moving conveyor to form a fiber web Step (d) Step of applying partial thermocompression to the obtained fiber web

The spunbonded nonwoven fabric of the present invention has excellent horizontal tensile strength, is excellent in formation and quality, and has stable and excellent mechanical strength. As a result, the spunbond nonwoven fabric of the present invention can be easily torn even when subjected to a large load, such as when a strong wind blows after being fixed and constructed on a base with a spelling needle in use as a house wrap material. There is nothing.

According to the method for producing a spunbonded nonwoven fabric of the present invention, a spunbonded nonwoven fabric having excellent horizontal tensile strength, excellent formation and quality, and stably having excellent mechanical strength is easily produced. can do.

FIG. 1 is a schematic view of a production process of a spunbonded nonwoven fabric showing an embodiment of the present invention. FIG. 2 is a schematic view of a nozzle that oscillates at a predetermined angle with respect to the web traveling direction according to an embodiment of the present invention.

In the spunbond nonwoven fabric of the present invention, it is important that the fiber orientation degree distribution peak of the thermoplastic continuous filament with respect to the longitudinal direction of the nonwoven fabric is 10 to 50 degrees. The angle is preferably 15 to 45 degrees, more preferably 20 to 40 degrees. When the peak of the fiber orientation degree is smaller than 10 degrees, the vertical / horizontal ratio of the tensile strength increases, and it is not easy to improve the horizontal tensile strength. On the other hand, if the peak of the fiber orientation degree is larger than 50 degrees, the vertical tensile strength decreases.

Here, the above-mentioned “fiber orientation degree” means an average inclination angle (acute angle) of the filament with respect to the vertical direction. More specifically, for example, 15 small sample pieces are randomly collected from a non-woven fabric, photographed 100 to 1000 times with a scanning electron microscope, and 15 pieces from each sample, totaling 225 fibers, The inclination angle (acute angle) when the direction is 0 degree and the horizontal direction is 90 degrees is measured, and the first decimal place of those average values is rounded off. Round off the first decimal place of the inclination angle of each fiber measured above to obtain an integer inclination angle, graph the fiber inclination angle on the horizontal axis and the frequency on the vertical axis, The inclination angle with a large amount was defined as “peak of fiber orientation distribution”.

The vertical direction of the spunbond nonwoven fabric of the present invention refers to a direction orthogonal to the width direction (horizontal direction) in a nonwoven fabric having a width or a nonwoven fabric having a known width direction. Even if the position of both the horizontal direction (the direction of width) and the vertical direction (the direction perpendicular to the width direction) is known in cut samples, it is possible to distinguish which is the horizontal direction and which is the vertical direction. In the case where there is not, in the spunbonded nonwoven fabric, since the tensile strength is generally stronger in the vertical direction than in the horizontal direction, the direction having the higher tensile strength can be set as the vertical direction. Further, when the width direction is not known at all with a cut sample or the like, the vertical direction can be determined by the following method.

First, four types of tensile tests are performed on cut samples every 45 °. Subsequently, tensile tests are performed every 15 ° between the two strongest directions. In addition, tensile tests are performed every 5 ° between the two strongest directions. Finally, a tensile test is performed every 1 ° in the two strongest directions, and the direction having the strongest tensile strength is defined as the vertical direction.

The tensile strength warp / width ratio of the spunbonded nonwoven fabric of the present invention is important to be 1.3 to 1.8, preferably 1.32 to 1.75, more preferably 1.35 to 1.70. . The tensile strength vertical / horizontal ratio is obtained by dividing the vertical tensile strength by the horizontal tensile strength.

The spunbonded nonwoven fabric of the present invention preferably has a tensile strength (hereinafter also referred to as a horizontal tensile strength) in the horizontal direction (width direction of the nonwoven fabric) of 90 N / 5 cm or more. By setting the horizontal tensile strength to 90 N / 5 cm or more, more preferably 95 N / 5 cm or more, excellent mechanical strength suitable for house wrap material applications can be obtained, and after fixing and constructing with a spelling needle, it is strong. It is prevented from being easily broken without being able to withstand the load when the wind blows.

In addition, the horizontal tensile strength is preferably 150 N / 5 cm or less, more preferably 145 N / 5 cm or less, whereby excellent mechanical strength suitable for house wrap materials can be obtained for both vertical and horizontal. In addition, said horizontal tensile strength is measured based on 6.3 "standard time" of 6.3 "tensile strength and elongation rate" of JIS L1913: 2010 "General nonwoven fabric test method".

The fiber ratio of the fiber orientation degree of the spunbonded nonwoven fabric of the present invention is preferably 60 to 80%, more preferably 60 to 75%, and further preferably 60 to 70%. By setting the fiber ratio of the fiber orientation degree of 10 to 50 degrees to 60 to 80%, it is possible to obtain a spunbonded nonwoven fabric having excellent mechanical strength in both vertical and horizontal directions and having good formation and quality. Can do.

The horizontal tensile strength per unit weight of the spunbonded nonwoven fabric of the present invention is preferably 2.2 N / 5 cm / (g / m ² ) or more, more preferably 2.3 (N / 5 cm) / (g / cm ^2). ) Or more, more preferably 2.4 (N / 5 cm) / (g / cm ² ) or more. The horizontal tensile strength per unit weight is obtained by dividing the horizontal tensile strength by the basis weight.

By setting the horizontal tensile strength per unit weight to 2.2 N / 5 cm / (g / m ² ) or more, excellent mechanical strength suitable for house wrap material use can be obtained. Further, the horizontal tensile strength per unit weight is preferably 3.8 (N / 5 cm) / (g / cm ² ) or less, more preferably 3.7 (N / 5 cm) / (g / cm ² ) or less. Thus, in use as a house wrap, it is possible to achieve both mechanical strength and handleability that can be put to practical use.

The thermoplastic continuous filament constituting the spunbonded nonwoven fabric of the present invention is preferably a composite filament in which a low melting point polymer having a melting point lower than the melting point of the high melting point polymer is disposed around the high melting point polymer. . By doing so, a thermoplastic continuous filament adhere | attaches firmly in a nonwoven fabric by thermocompression bonding, and can suppress fuzzing. Moreover, the mechanical strength suitable for use as a house wrap material can be provided. Moreover, by using such composite filaments, the filaments constituting the nonwoven fabric are firmly bonded to each other, and the number of adhesion points in the nonwoven fabric is also higher than that obtained by mixing fibers made of a low melting point polymer. Therefore, the dimensional stability and durability as a spunbonded nonwoven fabric can be improved.

Examples of the polymer that forms the thermoplastic continuous filament include polyester, polyamide, polyolefin, and a mixture or copolymer thereof. Of these, polyester is preferred because it is more excellent in durability such as mechanical strength, heat resistance, water resistance and chemical resistance.

Polyester consists of an acid component and an alcohol component. Examples of the acidic component include aromatic carboxylic acids such as terephthalic acid, isophthalic acid, and phthalic acid, aliphatic dicarboxylic acids such as adipic acid and sebacic acid, and alicyclic dicarboxylic acids such as cyclohexanecarboxylic acid. As the alcohol component, ethylene glycol, diethylene glycol, polyethylene glycol, or the like can be used. Examples of polyesters include polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, polylactic acid, polybutylene succinate, and copolymers thereof.

As the polymer forming the thermoplastic continuous filament, a biodegradable resin is also preferable because it can be easily discarded after use and has a low environmental impact. Examples of the biodegradable resin include polylactic acid, polybutylene succinate, polycaprolactone, polyethylene succinate, polyglycolic acid, polyhydroxybutyrate and the like. Among these, polylactic acid is preferable because it is a plant-derived resin that does not deplete petroleum resources, has relatively high mechanical properties and heat resistance, and low manufacturing costs.

The difference in melting point between the high melting point polymer and the low melting point polymer is preferably 10 to 140 ° C. Desirable thermal adhesiveness can be obtained by setting the difference in melting point to 10 ° C. or higher, more preferably 20 ° C. or higher, and further preferably 30 ° C. or higher. In addition, by controlling the temperature to 140 ° C. or lower, more preferably 120 ° C. or lower, and further preferably 100 ° C. or lower, it is possible to prevent the low melting point polymer component from fusing to the thermocompression-bonding roll during thermocompression bonding, thereby reducing productivity. Can do.

The melting point of the high melting point polymer in the composite fiber is preferably 160 to 320 ° C. By setting the temperature to 160 ° C. or higher, more preferably 170 ° C. or higher, and further preferably 180 ° C. or higher, the shape stability is excellent even in a processing step where heat is applied. Moreover, it suppresses that productivity is reduced by consuming a great deal of heat energy for melting at the time of producing the long-fiber nonwoven fabric by setting it to 320 ° C. or less, more preferably 300 ° C. or less, and even more preferably 280 ° C. or less. Can do.

Specific examples of the combination of the high melting point polymer and the low melting point polymer (high melting point polymer / low melting point polymer) include polyethylene terephthalate / polybutylene terephthalate, polyethylene terephthalate / polytrimethylene terephthalate, polyethylene terephthalate / polylactic acid, Examples thereof include polyethylene terephthalate / copolymerized polyethylene terephthalate. As a copolymerization component of copolymerized polyethylene terephthalate, isophthalic acid or the like is preferable.

The proportion of the low melting point polymer in the composite fiber is preferably 10 to 70% by mass. Desirable thermal adhesiveness can be obtained by setting the content to 10% by mass or more, more preferably 15% by mass or more, and further preferably 20% by mass or more. Moreover, 70 mass% or less, More preferably, it is 60 mass% or less, More preferably, it can suppress that fusion | bonding advances too much and tearing strength falls by setting it as 50 mass% or less.

Examples of the composite form of such a composite fiber include a concentric core-sheath type, an eccentric core-sheath type, a sea-island type, and a bimetal type. Among these, the concentric core-sheath type is preferable in that the fibers can be firmly bonded to each other by thermocompression bonding.

Also, examples of the cross-sectional shape of the thermoplastic continuous filament include a circular shape, a flat shape, a polygonal shape, a multi-leaf shape such as an X shape and a Y shape, and a hollow shape. In the case of adopting a deformed cross-sectional shape in the composite fiber as described above, it is preferable that the low melting point polymer component is present in the vicinity of the outer peripheral portion of the fiber cross-section so that it can contribute to thermocompression bonding.

The crystal bond agent, matting agent, lubricant, pigment, fungicide, antibacterial agent, flame retardant, hydrophilic agent and the like may be added to the spunbond nonwoven fabric of the present invention. Especially when thermocompression molding of long fiber nonwoven fabrics, metal oxides such as titanium oxide have the effect of improving the adhesion of long fiber nonwoven fabrics by increasing the thermal conductivity, and the mold release property between the thermocompression roll and web. It is preferable to add an aliphatic bisamide such as ethylenebisstearic acid amide and / or an alkyl-substituted aliphatic monoamide, which has an effect of improving the adhesion stability by increasing the number. These various additives may be present in the thermoplastic continuous filament or may be present on the surface of the thermoplastic continuous filament.

In the present invention, the fiber diameter of the thermoplastic continuous filament is preferably 10 to 24 μm. By setting the thickness to 10 μm or more, more preferably 12 μm or more, it is possible to obtain a nonwoven fabric excellent in basis weight uniformity and mechanical strength. In addition, by making the thickness not more than 24 μm, more preferably not more than 22 μm, it is possible to suppress excessive penetration of the hot melt resin used for bonding to the polyethylene perforated film into the nonwoven fabric when manufacturing the house wrap material. It is possible, and the adhesive strength between the film and the nonwoven fabric is also good, which is preferable as a house wrap material. In addition, when multiple types of fibers are mixed, it is preferable that the average single fiber diameter of each fiber is in the above range.

It is important that the spunbonded nonwoven fabric of the present invention is partially thermocompression bonded. By being partially thermocompression bonded, the fibers can be integrated to obtain mechanical strength that can withstand long-term use as a house wrap material.

The spunbond nonwoven fabric of the present invention preferably has a partial thermocompression bonding portion with an area ratio of 8 to 30%. By setting the area ratio to 8% or more, more preferably 9% or more, and even more preferably 10% or more, the strength of the nonwoven fabric can be improved, and surface fuzz can be suppressed. Further, by setting the area ratio to 30% or less, more preferably 28% or less, and still more preferably 24% or less, it is possible to appropriately leave voids between the fibers and suppress a decrease in tensile elongation and tear strength of the nonwoven fabric. it can.

Here, the partial thermocompression bonding part is formed such that at least one surface of the sheet forms a recess, and the thermoplastic continuous filaments constituting the nonwoven fabric are fused together by heat and pressure. That is, the portion where the thermoplastic continuous filaments are fused and aggregated compared to other portions is the partial thermocompression bonding portion.

The area ratio of the partial thermocompression bonding part is the ratio of the partial thermocompression bonding part over the entire surface of the spunbond nonwoven fabric, and when the partial thermocompression bonding part forms a pattern pattern by arranging repeating units, It is obtained by dividing the area of the partial thermocompression bonding part contained in one repeating unit by the area of the repeating unit. For the area ratio of the partial thermocompression bonding part, use the surface observation image of the spunbonded nonwoven fabric with a scanning electron microscope, or the surface shape data with a non-contact type shape measuring instrument such as a shape analysis laser microscope or 3D shape measuring machine. Or can be calculated. The area ratio of the partial thermocompression bonding part is obtained by averaging the area ratios measured at least at five or more repeating units.

The mechanical strength such as tensile strength and tear strength of the spunbond nonwoven fabric of the present invention varies depending on the basis weight of the nonwoven fabric. The basis weight of the spunbonded nonwoven fabric of the present invention is not limited to a specific value, but is preferably 30 to 60 g / m ² . By setting the basis weight to 30 g / m ² or more, more preferably 35 g / m ² or more, a spunbonded nonwoven fabric excellent in mechanical strength and suitable for use as a house wrap material can be obtained. In addition, by using a basis weight of 60 g / m ² or less, more preferably 55 g / m ² or less, when used as a house wrap material, it becomes a weight suitable for an operator to hold in the hand during construction. The rigidity is not too strong, and it is excellent in handleability during construction. Moreover, it can suppress that a loud sound comes out at the time of wind blowing.

The basis weight uniformity of the spunbonded nonwoven fabric of the present invention varies depending on the fiber diameter of the thermoplastic continuous filament. The basis weight CV of the spunbonded nonwoven fabric of the present invention is preferably 14.0% or less. By setting the basis weight CV to 14.0% or less, more preferably 13.0% or less, and even more preferably 12.0% or less, it is excellent in formation and mechanical strength, has little variation in physical properties, and is used as a house wrap material. A spunbonded nonwoven fabric that stably satisfies the physical properties required for use can be obtained. Further, the basis weight CV is preferably 2.0% or more, more preferably 2.5% or more, and further preferably 3.0% or more, so that the interval in the width direction of the filament spray nozzle in the cloth making process is extremely reduced. It is possible to prevent the manufacturing process from becoming complicated by narrowing or introducing a complicated fiber opening device.

For example, as shown in FIG. 1, the method for producing a spunbonded nonwoven fabric of the present invention is obtained by melting and extruding a thermoplastic polymer from a spinneret 1 and then pulling and stretching it by an ejector 2 and an air soccer 3 to make a thermoplastic continuous filament. Then, this is sent out from the nozzle 4 and charged and opened by the charging means 5 and then deposited on the moving collection surface 6. Thereby, it forms in the fiber web 7 with said filament.

The spinning speed of the thermoplastic continuous filament is preferably 3500 m / min or more. By setting the spinning speed to 3500 m / min or more, more preferably 3800 m / min or more, and even more preferably 4000 m / min or more, the sheet shrinks or wrinkles during thermocompression, or the sheet is taken up by a roll. It is possible to prevent the transportability from deteriorating. In addition, the spinning speed is preferably 6000 m / min or less, more preferably 5500 m / min or less, and even more preferably 5000 m / min or less to prevent the fibers from being excessively oriented and crystallized. Strength can be imparted.

As shown in FIG. 2, it is important that the nozzle 4 is directed to an angle (α) within a range of 5 to 25 degrees to the left or right with respect to the web traveling direction (longitudinal direction D). In the method for producing a spunbonded nonwoven fabric of the present invention, the filament is opened by swinging the nozzle 4, and the angle α is a central angle when the nozzle 4 is swung. It is important that the angle α is 5 degrees or more, preferably 8 degrees or more, more preferably 10 degrees or more, so that the fiber orientation degree distribution peak is 10 degrees or more, and the horizontal tensile strength is excellent. It can be a non-woven fabric with good formation and quality. On the other hand, it is important that the angle α is 25 degrees or less, preferably 20 degrees or less, more preferably 15 degrees or less, so that the fiber orientation degree distribution peak is 50 degrees or less and the tensile strength in the vertical direction is reduced. (Hereinafter, also referred to as vertical tensile strength) can be suppressed.

The angle (α) of the nozzle 4 can be individually set within a range of 5 to 25 degrees, but when the nozzles are arranged in a line in a direction perpendicular to the web traveling direction (longitudinal direction D), It is preferable that the direction in which all the nozzles face is unified in the right direction or the left direction. By doing in this way, it can prevent that filaments interfere and formation is deteriorated. Furthermore, when arranging a plurality of nozzles as described above, it is preferable that at least one row of nozzles is directed rightward and at least one row of nozzles is directed leftward. By doing in this way, it is set as a nonwoven fabric with good formation and quality, and the basis weight of the end portion is reduced, or there is a difference in tensile strength between the right oblique direction and the left oblique direction with respect to the web traveling direction (longitudinal direction D). Can be suppressed.

At this time, as shown in FIG. 2, it is important that the nozzle 4 is continuously swung at a predetermined angle (θ) of ± 10 degrees or more around the direction of the angle α. The filament passes through the continuously oscillating nozzle 4 and is then charged and opened by the charging means 5 to become a fiber web. The oscillation angle θ is ± 10 degrees or more, preferably ± 13 degrees or more, More preferably, by setting it to ± 16 degrees or more, it is possible to reduce the number of bundle-like fibers and improve the formation of the fiber web after being deposited on the conveyor. Thereby, the dispersion | variation in the mechanical strength of a fiber web can be reduced. On the other hand, the swing angle θ of the nozzle 4 is ± 25 degrees or less, more preferably ± 23 degrees or less, and further preferably ± 20 degrees or less with respect to the angle α, so that the nozzle 4 is deposited on the moving collection surface. Thus, when the fiber web 7 is formed, it is possible to suppress the occurrence of defects such as web curling.

The number of oscillations (reciprocations) per second of the continuously oscillating nozzle 4 is preferably 1.0 or more, more preferably 1.5 or more, and even more preferably 2.0 or more, The formation of the fiber web after being deposited on the conveyor can be improved. Further, the number of oscillations (reciprocations) per second is preferably 6.0 times or less, more preferably 5.5 times or less, and even more preferably 5.0 times or less, so that the thermoplastic continuous filament can be used as a nozzle. Therefore, it is possible to prevent the fibers from being bundled and to suppress the deterioration of the formation.

The charging method of the thermoplastic continuous filament is not limited at all, but charging by a corona discharge method or charging by frictional charging with a metal is preferable.

In the method for producing a spunbonded nonwoven fabric of the present invention, the speed of the moving conveyor is preferably 3 m / min or more, more preferably 4 m / min or more, and even more preferably 5 m / min or more. It can prevent the productivity from becoming low. Moreover, the speed of the moving conveyor is preferably 100 m / min or less, more preferably 90 m / min or less, and even more preferably 80 m / min or less, thereby suppressing the drawback that the web on the moving collection surface is curled. It is possible to prevent the sheet from being taken on a roll and the transportability is deteriorated.

In the method for producing a spunbonded nonwoven fabric of the present invention, as a means for providing a partial thermocompression bonding part, adhesion by an embossing roll heated to a predetermined temperature or adhesion by an ultrasonic oscillator can be preferably employed. In particular, adhesion by a hot embossing roll heated to a predetermined temperature is preferable in terms of improving the strength of the nonwoven fabric.

When thermocompression bonding is performed by the embossing roll 9, a portion where the thermoplastic continuous filaments are fused and aggregated by the convex portion of the embossing roll 9 becomes a thermocompression bonding portion. The embossing roll 9 is not limited to a specific shape or structure as long as the nonwoven fabric can be partially thermocompression bonded. For example, as shown in FIG. 1, a roll 9 a having a predetermined pattern of protrusions only on the upper side (or lower side) can be used, and a flat roll 9 b having no irregularities on the peripheral surface can be used for the other rolls. In this case, the thermocompression bonding portion refers to a portion in which the thermoplastic continuous filaments of the nonwoven fabric are aggregated by thermocompression bonding between the convex portion of one roll 9a and the flat peripheral surface of the other roll 9b.

In addition, the embossing roll 9 includes, for example, a pair of upper roll 9a and lower roll 9b having a plurality of parallel ridges formed on the surface, and both

rolls

9a and 9b face each other. In the thermocompression bonding position, a protrusion provided so that the protrusions of the upper roll 9a and the protrusions of the lower roll 9b cross each other can be used. In this case, the partial thermocompression bonding portion refers to a portion in which the thermoplastic continuous filaments of the nonwoven fabric are aggregated by thermocompression bonding with the ridges of the upper roll 9a and the ridges of the lower roll 9b. In this case, a portion sandwiched between the convex strip of the upper roll 9a and the concave groove of the lower roll 9b, or the concave groove of the upper roll 9a and the convex strip of the lower roll 9b is included in the thermocompression bonding section here. I can't. When the embossing roll 9 composed of a pair of

rolls

9a and 9b having a plurality of ridges on the surface is used, the parallelogram or rectangular heat is formed by the ridges of the upper roll 9a and the ridges of the lower roll 9b. It is preferable to form the pressure-bonding portion because the nonwoven fabric can be favorably bonded without peeling off.

The heating temperature of the embossing roll 9 is preferably a melting point of −60 ° C. to a melting point of −5 ° C. with respect to the melting point of the polymer having the lowest melting point among the polymers forming the thermoplastic continuous filament. When the heating temperature of the embossing roll 9 is set to the above melting point −60 ° C. or more, more preferably the above melting point −50 ° C. or more, the thermal bonding can be efficiently performed and the transverse tensile strength can be improved. . On the other hand, when the heating temperature of the embossing roll 9 is set to the above melting point −5 ° C. or less, more preferably the above melting point −10 ° C. or less, the roll fouling caused by the fibers being fused to the embossing roll 9 during the production of the nonwoven In addition, it is possible to suppress fusion of non-woven fabric surface fibers other than the partially thermocompression-bonded portion. As a result, when used as a house wrap material, the texture is not too stiff, it is excellent in handling at the time of construction, and it has moderate suppleness, so it suppresses the generation of loud noise when blowing in the wind it can.

As the shape of the thermocompression bonding portion, any shape other than a circle, a triangle, a quadrangle, a parallelogram, an ellipse, a rhombus and the like can be adopted. In addition, the arrangement of the thermocompression bonding parts may be one regularly arranged at equal intervals, one randomly arranged, or a mixture of different shapes. Among these, from the viewpoint of uniformity of the nonwoven fabric, those in which the thermocompression bonding portions are arranged at equal intervals are preferable.

In the method for producing the spunbonded nonwoven fabric of the present invention, a pair of flat rolls 8a, as shown in FIG. You may perform a press-contact process by 8b.

The above-mentioned pressure contact treatment with the flat roll 8b is not limited as long as the flat roll 8b is brought into contact with the fiber web 7, but heat treatment for bringing the heated flat roll 8b into contact with the fiber web 7 is preferable.

The surface temperature of the flat roll 8b in this heat treatment is preferably 30 to 120 ° C. lower than the melting point of the polymer having the lowest melting point constituting the filament existing on the surface of the fiber web 7. That is, when this melting point is (Tm), the surface temperature of the flat roll 8b is preferably (Tm-30) to (Tm-120) ° C, more preferably (Tm-40) to (Tm-110) ° C. (Tm-50) to (Tm-100) ° C. is most preferable. When the surface temperature of the flat roll 8b is lower than (Tm−120) ° C., the heat treatment of the fiber web (7) becomes insufficient, and the target sheet thickness cannot be obtained and the adhesion becomes insufficient. This is not preferable because the effect of improving the transportability cannot be obtained. On the other hand, when the surface temperature of the flat roll 8b is higher than (Tm-30) ° C., the heat treatment becomes too strong, and the constituent fibers of the surface layer portion are in a fused state, and a sufficient mechanical strength cannot be obtained. .

As a method for bringing the flat roll 8b into contact with the flat roll 8b, a method in which the fiber web is continuously brought into contact with the flat roll 8b and heat-treated as shown in FIG. 1 or a method in which heat treatment is performed by being sandwiched between a pair of flat rolls is used. it can.

Next, the examples of the spunbonded nonwoven fabric of the present invention will be described more specifically by way of examples. However, the present invention is not limited to those described in these examples. In addition, each characteristic value in an Example and a comparative example was measured with the following measuring method.

(1) Melting point (° C)
Using a differential scanning calorimeter DSC-2 manufactured by Perkin Elma Co., Ltd., measurement was performed under the condition of a heating rate of 20 ° C./min, and the temperature giving an extreme value in the obtained melting endotherm curve was defined as the melting point. Further, for a resin whose melting endotherm curve does not show an extreme value in a differential scanning calorimeter, the resin was heated on a hot plate, and the temperature at which the resin was completely melted by microscopic observation was taken as the melting point.

(2) Intrinsic viscosity IV
The intrinsic viscosity IV of the polyethylene terephthalate resin was measured by the following method.
8 g of a sample was dissolved in 100 ml of orthochlorophenol, and a relative viscosity η _r was determined by the following formula using an Ostwald viscometer at a temperature of 25 ° C.
η _r = η / η ₀ = (t × d) / (t ₀ × d ₀ )
Where η: viscosity of polymer solution η ₀ : viscosity of orthochlorophenol t: drop time of solution (seconds)
d: density of the solution (g / cm ³ )
t ₀ : Fall time of orthochlorophenol (seconds)
d ₀ : Orthochlorophenol density (g / cm ³ )
It is.
Then, from the obtained relative viscosity η _r , the following formula IV = 0.0242 η _r +0.2634
Thus, the intrinsic viscosity IV was calculated.

(3) Average single fiber diameter (μm)
Ten small sample samples were taken at random from the non-woven fabric, photographed with a scanning electron microscope at a magnification of 500 to 7000 times, the diameter of 100 fibers, 10 from each sample, were measured, and the average Calculated by rounding off the first decimal place.

(4) Weight per unit (g / m ² )
Three 50 cm × 50 cm nonwoven fabrics were sampled, the weight of each sample was measured, the average value of the obtained values was converted per unit area, and the first decimal place was rounded off.

(5) Degree of fiber orientation (degree)
A small sample of 15 pieces was randomly collected from the nonwoven fabric, and a 500 times magnification photograph was taken with a scanning electron microscope. A total of 225 fibers, 15 from each sample, was set to a vertical direction of 0 degree and a horizontal direction of 90 degrees. The angle when measured in degrees was measured, and the first degree after the decimal point was rounded off to obtain the fiber orientation degree.

(6) Tensile strength (N / 5cm)
In accordance with 6.3 “Standard time” of 6.3 “Tensile strength and elongation” of JIS L 1913: 2010 “General nonwoven fabric test method”, the tensile strength was measured by the following method. Ten specimens having a length of 300 mm and a width of 50 mm were collected in the vertical direction and the horizontal direction of the nonwoven fabric. The test piece is subjected to a tensile test with a constant speed extension type tensile tester at a gripping interval of 200 mm and a tensile speed of 200 ± 10 mm / min, and the strength (N) at the maximum load until breaking is about 0.1N. This was determined as the tensile strength (N / 5 cm).

(7) Weight per unit area (%)
16 pieces of 5cm x 5cm pieces are collected in the vertical and horizontal directions, and a total of 256 pieces are collected. The mass of each sample (nonwoven fabric) is measured, and the average value of the obtained values is converted per unit area. The first decimal place was rounded off to determine the basis weight of the nonwoven fabric. Based on this basis weight, the CV value was calculated by the following formula, and the second decimal place was rounded off.
C basis weight CV (%) = (standard deviation of basis weight) / (average value of basis weight) × 100.

(8) Quality evaluation In a roll of 200 cm in the width direction and 1000 m in the longitudinal direction, the number of occurrences of defects that wrinkle was visually counted, and the surface quality was evaluated according to the following criteria. Judgment criteria were “◎” and “○” as acceptable. Wrinkle defects are those where the fiber web deposited on the moving conveyor is affected by the air flow during transportation, and only the surface layer is rolled up and thermocompression bonded in a folded state, resulting in a dark area This is a disadvantage that a portion with a thin basis weight is generated adjacently.
◎: No flaws are generated. ○: One defect is generated. △: Two or more defects are generated. ×: Four or more defects are generated.

[Example 1]
(Fiber web)
A core component was obtained by drying a polyethylene terephthalate resin having an intrinsic viscosity of 0.65 and a melting point of 260 ° C. and containing 0.3% by mass of titanium oxide to a moisture content of 50 ppm or less. In addition, a sheath component is obtained by drying a copolymerized polyethylene terephthalate resin containing an intrinsic viscosity of IV 0.66, an isophthalic acid copolymerization rate of 10 mol%, a melting point of 230 ° C., and containing 0.2% by mass of titanium oxide to a moisture content of 50 ppm or less. did.

The core component was melted at 295 ° C. and the sheath component was melted at 280 ° C., and the composite ratio of core / sheath was 80/20 in mass ratio to form a concentric core-sheath type with a circular cross section. After spinning, spinning with an air soccer at a spinning speed of 4300 m / min was made into a thermoplastic continuous filament. Then, this filament is passed through a nozzle swinging at an angle θ of ± 18 degrees around the angle α, with the angle α directed to the right by 15 degrees with respect to the web traveling direction, and a metal collision plate installed at the nozzle outlet The filaments were made to collide with each other, and the fibers were charged and opened by frictional charging, and collected as a fiber web on a moving conveyor (moving collection surface). The moving speed of the conveyor was adjusted so that the collected fiber web had a basis weight of 40 g / m ² .

(Thermo-compression bonding)
The fiber web is thermocompression bonded at a flat roll surface temperature of 150 ° C. and a linear pressure of 60 kg / cm with a pair of upper and lower flat rolls, and then with a pair of embossing rolls under conditions of a surface temperature of 190 ° C. and a linear pressure of 70 kg / cm. Partial thermocompression was applied. The embossing roll used is composed of an upper roll in which a plurality of ridges arranged in parallel on the surface are formed annularly in the circumferential direction, and a lower roll in which a plurality of ridges are formed in a spiral on the surface. Become. At the thermocompression bonding position where both rolls face each other, the ridges of the upper roll and the ridges of the lower roll are crossed, and the crimping part is thermocompression bonded between the ridges of the upper roll and the ridges of the lower roll. The area ratio with respect to the whole nonwoven fabric is adjusted to 18%.

By the above treatment, a spunbonded nonwoven fabric having a fiber diameter of 16 μm and a basis weight of 40 g / m ² was obtained. The obtained spunbonded nonwoven fabric had a fiber orientation degree distribution peak of 35 degrees, a transverse tensile strength of 106 N / 5 cm, and a tensile strength warp / width ratio of 1.37. The results are shown in Table 1.

[Example 2]
The fiber web was collected in the same manner as in Example 1 except that the angle α was directed 10 degrees to the left with respect to the web traveling direction, and a nozzle that swung ± 18 degrees around the angle α was passed.
Thereafter, a spunbonded nonwoven fabric having a fiber diameter of 16 μm and a basis weight of 40 g / m ² was obtained by the same thermocompression treatment as in Example 1. The resulting spunbonded nonwoven fabric of Example 2 had a fiber orientation degree distribution peak of 30 degrees, a transverse tensile strength of 97 N / 5 cm, and a tensile strength warp / width ratio of 1.54.

[Example 3]
The fiber web was collected in the same manner as in Example 1 except that the angle α was directed rightward by 5 degrees with respect to the web traveling direction, and a nozzle that swung ± 18 degrees around the angle α was passed.
Thereafter, a spunbonded nonwoven fabric having a fiber diameter of 16 μm and a basis weight of 40 g / m ² was obtained by the same thermocompression treatment as in Example 1. The obtained spunbonded nonwoven fabric of Example 3 had a fiber orientation degree distribution peak of 25 degrees, a horizontal tensile strength of 93 N / 5 cm, and a tensile strength vertical / horizontal ratio of 1.67.

[Example 4]
The fiber web was collected in the same manner as in Example 1 except that the angle α was directed rightward by 10 degrees with respect to the web traveling direction, and the nozzle was swung at ± 20 degrees around the angle α.
Thereafter, a spunbonded nonwoven fabric having a fiber diameter of 16 μm and a basis weight of 40 g / m ² was obtained by the same thermocompression treatment as in Example 1. The resulting spunbonded nonwoven fabric of Example 4 had a fiber orientation degree distribution peak of 40 degrees, a horizontal tensile strength of 95 N / 5 cm, and a tensile strength vertical / horizontal ratio of 1.53.

[Example 5]
The discharge amount is adjusted so that the fiber diameter becomes 14 μm, the angle α is turned 10 degrees to the left with respect to the web traveling direction, the nozzle swinging ± 13 degrees around the angle α is passed, and the basis weight is 40 g. The fiber web was collected in the same manner as in Example 1 except that the moving speed of the conveyor for collecting the fiber web was adjusted to be / m ² .
Thereafter, a spunbonded nonwoven fabric having a fiber diameter of 14 μm and a basis weight of 40 g / m ² was obtained by the same thermocompression treatment as in Example 1. The resulting spunbonded nonwoven fabric of Example 5 had a fiber orientation degree distribution peak of 15 degrees, a transverse pulling strength of 105 N / 5 cm, and a tensile strength warp / width ratio of 1.79.

[Example 6]
The fiber web was collected in the same manner as in Example 5 except that the angle α was directed to the left at 15 degrees with respect to the web traveling direction, and the nozzle was swung at ± 13 degrees around the angle α.
Thereafter, a spunbonded nonwoven fabric having a fiber diameter of 14 μm and a basis weight of 40 g / m ² was obtained by the same thermocompression treatment as in Example 1. The obtained spunbonded nonwoven fabric of Example 6 had a fiber orientation degree distribution peak of 20 degrees, a transverse pulling strength of 110 N / 5 cm, and a tensile strength warp / width ratio of 1.68.

[Example 7]
The fiber web was collected in the same manner as in Example 5 except that the angle α was directed to the left by 12 degrees with respect to the web traveling direction, and the nozzle was swung at ± 15 degrees around the angle α.
Thereafter, an embossing roll having a regular convex portion of a circular pattern on the upper side and a flat roll having no irregularities on the lower side, and a fiber diameter of 14 μm by a thermocompression treatment with an area ratio of the pressure-bonding part to be thermocompression bonded to 10%. A spunbonded nonwoven fabric having a basis weight of 40 g / m ² was obtained. The obtained spunbonded nonwoven fabric of Example 7 had a fiber orientation degree distribution peak of 15 degrees, a horizontal tensile strength of 100 N / 5 cm, and a tensile strength vertical / horizontal ratio of 1.75.

[Example 8]
The fiber web was collected in the same manner as in Example 1 except that the moving speed of the conveyor for collecting the fiber web was adjusted so that the basis weight was 55 g / m ² .
Thereafter, a spunbonded nonwoven fabric having a fiber diameter of 16 μm and a basis weight of 55 g / m ² was obtained by the same thermocompression treatment as in Example 1. The spunbonded nonwoven fabric obtained in Example 8 had a fiber orientation degree distribution peak of 36 degrees, a transverse tensile strength of 138 N / 5 cm, and a tensile strength warp / width ratio of 1.69.

[Comparative Example 1]
The fiber web was collected in the same manner as in Example 1 except that the nozzle was swung at an angle α of 0 ° and an angle α of ± 18 ° with respect to the web traveling direction.
Thereafter, a spunbonded nonwoven fabric having a fiber diameter of 16 μm and a basis weight of 40 g / m ² was obtained by the same thermocompression treatment as in Example 1. The obtained spunbonded nonwoven fabric of Comparative Example 1 had a fiber orientation degree distribution peak of 5 degrees, a horizontal tensile strength of 85 N / 5 cm, and a tensile strength vertical / horizontal ratio of 2.00.

[Comparative Example 2]
The fiber web was collected in the same manner as in Example 1 except that the nozzle was swung at an angle α of 0 degree and about ± 25 degrees about the angle α with respect to the web traveling direction.
Thereafter, a spunbonded nonwoven fabric having a fiber diameter of 16 μm and a basis weight of 40 g / m ² was obtained by the same thermocompression treatment as in Example 1. The obtained spunbonded nonwoven fabric of Comparative Example 2 had a fiber orientation degree distribution peak of 8 degrees, a horizontal tensile strength of 130 N / 5 cm, and a tensile strength vertical / horizontal ratio of 1.22.

[Comparative Example 3]
The discharge amount is adjusted so that the fiber diameter is 14 μm, and the nozzle is swung at an angle α of 0 degree with respect to the web traveling direction and ± 13 degrees around the angle α, and the basis weight is 40 g / m ^2. The fiber web was collected in the same manner as in Example 5 except that the moving speed of the conveyor for collecting the fiber web was adjusted.
Thereafter, a spunbonded nonwoven fabric having a fiber diameter of 14 μm and a basis weight of 40 g / m ² was obtained by the same thermocompression treatment as in Example 1. The resulting spunbonded nonwoven fabric of Comparative Example 3 had a fiber orientation degree distribution peak of 2 degrees, a transverse tensile strength of 89 N / 5 cm, and a tensile strength warp / width ratio of 2.13.

[Comparative Example 4]
The fiber web was collected in the same manner as in Example 1 except that the angle α was directed to the right direction of 30 degrees with respect to the web traveling direction, and the nozzle was swung at ± 18 degrees around the angle α.
Thereafter, a spunbonded nonwoven fabric having a fiber diameter of 16 μm and a basis weight of 40 g / m ² was obtained by the same thermocompression treatment as in Example 1. The obtained spunbonded nonwoven fabric of Comparative Example 4 had a fiber orientation degree distribution peak of 55 degrees, a horizontal tensile strength of 110 N / 5 cm, and a tensile strength vertical / horizontal ratio of 1.18.

[Comparative Example 5]
The discharge amount is adjusted so that the fiber diameter is 14 μm, the angle α is directed leftward by 30 degrees with respect to the web traveling direction, the nozzle swinging ± 13 degrees around the angle α is passed, and the basis weight is 40 g. The fiber web was collected in the same manner as in Example 5 except that the moving speed of the conveyor for collecting the fiber web was adjusted to be / m ² .
Thereafter, a spunbonded nonwoven fabric having a fiber diameter of 14 μm and a basis weight of 40 g / m ² was obtained by the same thermocompression treatment as in Example 1. The obtained spunbonded nonwoven fabric of Comparative Example 5 had a fiber orientation degree distribution peak of 50 degrees, a horizontal tensile strength of 115 N / 5 cm, and a tensile strength vertical / horizontal ratio of 1.17.
The characteristics of the spunbonded nonwoven fabrics of the above examples and comparative examples are shown in Table 1 below.

As shown in Table 1, each of the spunbond nonwoven fabrics of Examples 1 to 8 has a fiber orientation degree distribution peak of 10 to 50 degrees and a tensile strength warp / width ratio of 1.3 to 1.8. Since it satisfies, it is a spunbonded nonwoven fabric having excellent horizontal tensile strength, good formation and quality, and suitable as a house wrap material.

On the other hand, the spunbonded nonwoven fabrics of Comparative Examples 1 and 3 all have a fiber orientation degree distribution peak of less than 10 degrees, and the tensile strength warp / width ratio does not satisfy 1.3 to 1.8. The horizontal tensile strength was low and it was not suitable as a house wrap material. In addition, the spunbonded nonwoven fabrics of Comparative Examples 2, 4, and 5 had many wrinkling defects and were not suitable as house wrap materials because they could not obtain good quality.

Although the present invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the invention. This application is based on a Japanese patent application (Japanese Patent Application No. 2016-210317) filed on Oct. 27, 2016, which is incorporated by reference in its entirety.

The spunbonded nonwoven fabric of the present invention is useful as a house wrap material because it has excellent horizontal tensile strength and has both texture and quality. In addition, the use of the spunbonded nonwoven fabric of the present invention is not limited to the above, for example, industrial materials such as filters, filter base materials, electric wire holding materials, wallpaper, roof covering materials, sound insulation materials, heat insulating materials, Building materials such as sound-absorbing materials, wrapping materials, bag materials, signboard materials, living materials such as printing base materials, grass protection sheets, drainage materials, ground reinforcement materials, sound insulation materials, sound-absorbing materials, etc., solid materials, light shielding It can be used for agricultural materials such as seats, vehicle materials such as ceiling materials, and spare tire cover materials.

DESCRIPTION OF SYMBOLS 1 ... Spinneret 2 ... Ejector 3 ... Air soccer 4 ... Nozzle 5 ... Charging means 6 ... Moving collection surface 7 ...

Fiber web

8a, 8b ... Flat roll 9 ... Embossing roll 9a ... One roll (upper roll)
9b ... the other roll (lower roll)
DESCRIPTION OF SYMBOLS 10 ... Nonwoven fabric 11 ... Heat-pressing part (alpha) ... Nozzle angle (theta) ... Swing angle D ... Web advancing direction (longitudinal direction)

Claims

A spunbonded nonwoven fabric that is partially thermocompression-bonded composed of thermoplastic continuous filaments, wherein the filament has a fiber orientation degree distribution peak in the vertical direction of 10 to 50 degrees with respect to the longitudinal direction of the nonwoven fabric. A spunbonded nonwoven fabric characterized by having a strong warp / width ratio of 1.3 to 1.8.
2. The spunbonded nonwoven fabric according to claim 1, wherein the fiber ratio of the fiber orientation degree is 10 to 50 degrees is 60 to 80%.
The spunbonded nonwoven fabric according to claim 1 or 2, wherein the transverse tensile strength per unit weight is 2.2 N / 5 cm / (g / m 2 ) or more.
4. The composite filament according to claim 1, wherein the thermoplastic continuous filament is a composite filament in which a low melting point polymer having a melting point lower than that of the high melting point polymer is arranged around the high melting point polymer. The spunbonded nonwoven fabric according to item 1.
The spunbond nonwoven fabric according to any one of claims 1 to 4, wherein the spunbond nonwoven fabric has a partial thermocompression bonding portion having an area ratio of 8 to 30%.
A house wrap material comprising the spunbonded nonwoven fabric according to any one of claims 1 to 5.
A method for producing a spunbonded nonwoven fabric, wherein the following (a) to (d) are sequentially performed.
(A) Step of obtaining a thermoplastic continuous filament by drawing and stretching the thermoplastic polymer from a spinneret and then drawing and stretching it with an air soccer (b) The obtained filament is 5 to 25 with respect to the web traveling direction. The step of swinging the spray nozzle directed in the direction of degrees within a range of ± 10 to ± 25 degrees to open the filament (c) depositing the opened filament on a moving conveyor to form a fiber web Step (d) Step of applying partial thermocompression to the obtained fiber web