JP3974889B2 - Laminated nonwoven fabric for wiper, method for producing the same, and wet wiper - Google Patents

Description

  The present invention relates to a laminated nonwoven fabric for wipers that has little liquid residue on an object after wiping and is excellent in wiping properties such as oil stains.

  Conventionally, wipers with little liquid remaining on the object after wiping include laminated wipers combining a hydrophobic fiber layer and a hydrophilic fiber layer, wipers having ultrafine fibers utilizing the capillary phenomenon of ultrafine fibers, etc. Has been proposed. As the laminated wiper, for example, in Japanese Utility Model Laid-Open No. 5-91550 (Patent Document 1) and Japanese Patent Laid-Open No. 9-276193 (Patent Document 2), a hydrophobic synthetic fiber layer is provided on one side or both sides of a hydrophilic fiber layer. A laminated wiper has been proposed which is laminated and has a hydrophobic synthetic fiber layer side as a wiping surface.

  Furthermore, as a wet type laminated wiper, for example, in Japanese Patent Application Laid-Open No. 9-234167 (Patent Document 3), upper and lower layers composed of 100 to 50% by weight of hydrophobic fibers and 0 to 50% by weight of hydrophilic fibers, and hydrophobic A wet tissue laminate composed of an intermediate layer composed of 0 to 20% by weight of fibers and 100 to 80% by weight of hydrophilic fibers has been proposed.

  As the latter wiper having ultrafine fibers, for example, JP-A-5-56903 (Patent Document 4) proposes a nonwoven fabric for wipers including ultrafine fibers that are mechanically divided and entangled.

Japanese Utility Model Publication No. 5-91550 Japanese Patent Laid-Open No. 9-276193 JP-A-9-234167 Japanese Patent Laid-Open No. 5-56903

  However, the wiper has various problems as follows. For example, in Japanese Utility Model Laid-Open No. 5-91550, Japanese Patent Laid-Open No. 9-234167, and Japanese Patent Laid-Open No. 9-234167, when the basis weight of the nonwoven fabric is reduced, the hydrophilic fiber layer and the hydrophobic synthetic fiber layer are When integrated by the hydroentanglement process, there was a mixed cotton state between the layers, and the liquid remaining on the object after wiping tended to increase.

Furthermore, in Japanese Patent Application Laid-Open No. 5-56903, by including ultrafine fibers that are mechanically divided and entangled, and having an apparent density of 0.05 to 0.13 g / cm ³ , wiping properties such as dirt can be obtained. Although excellent, the liquid remaining on the object after wiping was not sufficient. The present invention has been made in view of the above problems, and an object of the present invention is to obtain a laminated nonwoven fabric for a wiper and a wet wiper that have little liquid remaining on an object after wiping and have excellent wiping properties.

  The laminated nonwoven fabric for wipers of the present invention has a fineness of 0.9 dtex or less, and a fiber layer containing synthetic fibers is laminated on both sides of a fiber layer containing ultrafine fibers (va) containing a modified vinyl alcohol resin, It is characterized by being integrated by confounding.

  In the method for producing a laminated nonwoven fabric for wiper according to the present invention, a fiber layer containing a heat-shrinkable split composite fiber is laminated on both sides of a fiber layer containing a split composite fiber (VA) containing a modified vinyl alcohol resin as at least one component. (Hereinafter referred to as a laminated web), and after the ultrafine fiber (va) containing the modified vinyl alcohol resin is divided and expressed by hydroentanglement treatment, the laminated web is integrated, and then heat treatment is performed so that the area shrinkage rate is 10% or less. It is characterized by that.

  The wet wiper according to the present invention is characterized by containing a wetting agent in a range of 50 parts by mass or more and 300 parts by mass or less in 100 parts by mass of the laminated nonwoven fabric or the laminated nonwoven fabric obtained by the production method. .

  The laminated nonwoven fabric for wipers of the present invention has a fineness of 0.9 dtex or less, and a fiber layer containing synthetic fibers is laminated on both sides of a fiber layer containing ultrafine fibers (va) containing a modified vinyl alcohol resin, By adopting an integrated structure by entanglement, it is possible to reduce the amount of liquid remaining on the target surface when the target surface is wiped off, and to obtain a wiper that is excellent in wiping properties such as oil stains.

  Further, a fiber obtained by dividing and expressing the split type composite fiber (B) by the ultrafine fiber (b) on both surfaces of a fiber layer containing the split type composite fiber (VA) containing at least one component of a modified vinyl alcohol resin. And after the fiber layers containing the heat-shrinkable split-type composite fibers are laminated and integrated by hydroentanglement treatment, the split-type composite fibers (B) are heat-treated so that the area shrinkage rate is 10% or less. In this way, it is possible to reduce the amount of liquid remaining on the target surface, particularly when the target surface is wiped off, and to obtain a wiper that is excellent in wiping properties such as oil stains.

  The laminated nonwoven fabric for wipers of the present invention has little liquid remaining on the target surface when the target surface is wiped off and is excellent in wiping properties such as oil and fat stains. The wiper can be suitably used for a wiper that wipes off a target surface.

  The laminated nonwoven fabric for wipers of the present invention has a fineness of 0.9 dtex or less, and a synthetic fiber on both sides of a fiber layer containing ultrafine fibers (va) containing modified vinyl alcohol resin (hereinafter referred to as ultrafine fibers (va)). By laminating the fiber layers containing, and integrating them by hydroentanglement, the ultrafine fibers (va) are entangled not only inside the nonwoven fabric but also near the surface. Since the ultrafine fiber (va) is relatively easily wetted by a liquid such as water, the liquid can be absorbed into the nonwoven fabric by utilizing the capillary phenomenon of the ultrafine fiber (va) entangled near the surface of the nonwoven fabric. And less liquid remains on the object. Moreover, since the ultra fine fiber (va) is excellent in the adsorptivity with respect to the oil and fat component, the ultra fine fiber (va) entangled in the vicinity of the surface of the non-woven fabric can effectively hold the oil and fat component, and thus wipes off the oil stain. Excellent in properties. As a form of laminating a fiber layer containing synthetic fibers on both sides of a fiber layer containing ultrafine fibers (va), a three-layer structure in which the above three layers are laminated, a fiber layer containing ultrafine fibers (va) and synthesis Examples include a structure in which another sheet is laminated between the fiber layers containing fibers, and it is preferable to laminate so that the ultrafine fibers (va) are not exposed to the outermost layer of the laminated nonwoven fabric.

  On the other hand, when the laminated nonwoven fabric for wiper of the present invention is laminated on both surfaces of a fiber layer containing ultrafine fibers (va), as a synthetic fiber, a fiber layer containing ultrafine fibers (b) having a fineness of 0.9 dtex or less, The droplets can be made small, and it is excellent in wiping off dirt. The fiber layer containing synthetic fibers preferably forms the outermost layer of the laminated nonwoven fabric.

  The modified vinyl alcohol resin is a copolymer of vinyl alcohol and another monomer. Examples of other monomers include α-olefins such as ethylene, propylene, 1-butene, isoprene and 1-hexene. Especially, it is preferable that it is an ethylene-vinyl alcohol copolymer (henceforth EVOH) which has ethylene content in the range of 30 mol% or more and 50 mol% or less. This is because, according to the EVOH, the liquid does not get wet more than necessary with respect to a liquid such as water, and exhibits an appropriate wettability, so that the liquid absorbency when the laminated nonwoven fabric is made is excellent. Moreover, according to the EVOH, the oil and fat component adsorbability is excellent, and the oil and fat stain retention is excellent. A more preferable lower limit of the ethylene content is 35 mol%. The upper limit of more preferable ethylene content is 45 mol%.

  The fineness of the ultrafine fiber (va) is 0.9 dtex or less. The lower limit of the fineness of the preferred ultrafine fiber (va) is 0.05 dtex. The upper limit of the fineness of the preferred ultrafine fiber (va) is 0.6 dtex. The upper limit of the fineness of the ultrafine fiber (va) is more preferably 0.4 dtex. This is because if the fineness of the ultrafine fiber (va) exceeds 0.9 dtex, the liquid remaining on the object may increase.

  The ultrafine fiber (va) can be obtained, for example, by melt spinning a modified vinyl alcohol alone or in combination with another resin. Examples of the form of the fiber include a single type, a (eccentric) sheath core type, a parallel type, a split type, and a sea-island type. Especially, it is preferable that it is the fiber obtained by dividing and expressing the split type composite fiber (VA) which uses a modified vinyl alcohol resin as at least one component. This is because according to the split type composite fiber (VA), it is possible not only to express the ultrafine fiber (va) easily but also to easily adjust the content of the ultrafine fiber (va). Moreover, according to the split type composite fiber (VA), an ultrafine fiber composed of another resin can be developed simultaneously with the ultrafine fiber (va), which is advantageous for wiping. Furthermore, according to the split type composite fiber (VA), the shape of the ultrafine fiber after splitting has an irregular cross-sectional shape such as a fan shape or a trapezoidal shape, so that the wiping effect is improved, which is preferable. FIG. 1 shows an example of a fiber cross section of a split type composite fiber used in the present invention. In the case of a split type composite fiber (VA), the first component (1) can be used as a modified vinyl alcohol resin component, and the second component can be used as another resin component.

  The split type composite fiber (VA) is preferably a split type composite fiber having at least two components of a modified vinyl alcohol resin and a polyolefin resin. According to such a configuration, not only can the ultrafine fiber (va) and the polyolefin ultrafine fiber be easily expressed, but the ultrafine fiber (va) exhibiting appropriate wettability and the polyolefin ultrafine fiber exhibiting hydrophobicity are mixed. Since they are entangled, the wettability with respect to a liquid such as water can be adjusted. Examples of the polyolefin resin include resins such as polyethylene, polypropylene, polybutene-1, polymethylpentene, and copolymers thereof. Of these, polypropylene resin is preferable because of its excellent handleability.

  The fineness of the split type composite fiber (VA) may be appropriately set according to the fineness of the ultrafine fiber (va) to be obtained, but is preferably in the range of 0.5 dtex to 5 dtex. The lower limit of the fineness of the more preferable split type composite fiber (VA) is 1 dtex. The upper limit of the fineness of the more preferable split type composite fiber (VA) is 4.4 dtex. If the fineness of the split-type composite fiber (VA) is less than 0.5 dtex, the fiber productivity may be reduced. If the fineness of the split-type composite fiber (VA) exceeds 5 dtex, it is necessary to increase the number of splits in order to obtain ultrafine fibers (va), and the splittability may be reduced. Moreover, it is preferable that the division | segmentation number of a split type composite fiber (VA) exists in the range of 4 or more and 32 or less.

  The volume ratio (modified vinyl alcohol resin / other resin) between the modified vinyl alcohol resin and the other resin in the split type composite fiber (VA) is preferably in the range of 9/1 to 1/9. A more preferable volume ratio is 6/4 to 4/6. When the volume ratio of the modified vinyl alcohol resin to other resins in the split type composite fiber (VA) is less than 1/9, the content of the modified vinyl alcohol resin tends to decrease, and the liquid residue on the object tends to increase. It is in. When the volume ratio exceeds 9/1, the content of the modified vinyl alcohol resin increases, and the fiber productivity may be reduced.

  Next, examples of synthetic fibers include fibers composed of polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyamide resins such as nylon 6 and nylon 66, polyolefin resins such as polyethylene and polypropylene, and the like. Among these, it is preferable to contain an ultrafine fiber (b) having a fineness of 0.9 dtex or less. The minimum of the fineness of a preferable ultrafine fiber (b) is 0.05 dtex. The upper limit of the fineness of the preferred ultrafine fiber (b) is 0.6 dtex. The upper limit of the fineness of the ultrafine fiber (b) is more preferably 0.4 dtex. This is because if the fineness of the ultrafine fiber (b) exceeds 0.9 dtex, the amount of liquid remaining on the object tends to increase.

  Examples of the resin used for the ultrafine fiber (b) include polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyamide resins such as nylon 6 and nylon 66, and polyolefin resins such as polyethylene and polypropylene. Among them, the polyamide resin is preferable because it exhibits an appropriate wettability with respect to a liquid such as water and is excellent in wiping properties such as dirt.

  The ultrafine fiber (b) can be obtained, for example, by melt spinning the above resin alone or in combination of two or more kinds of resins. Examples of the form of the fiber include a single type, a (eccentric) sheath core type, a parallel type, a split type, and a sea-island type. Especially, it is preferable that an ultra fine fiber (b) is a fiber obtained by dividing and expressing a split type composite fiber (B). According to such a configuration, the ultrafine fiber (b) can be easily expressed.

  The split composite fiber (B) is preferably a split composite fiber having at least two components of a polyamide resin and a polyester resin. According to such a configuration, not only can the polyamide ultrafine fiber and the polyester ultrafine fiber be easily expressed, but the polyamide ultrafine fiber exhibiting appropriate wettability and the polyester ultrafine fiber exhibiting hydrophobicity are mixed and entangled. The liquid remaining on the object is small, and the wiping property is excellent, which is preferable. It is preferable that the volume ratio (polyamide resin / other resin) of the polyamide resin and the other resin in the split type composite fiber (B) is in the range of 9/1 to 1/9. A more preferable volume ratio is 6/4 to 4/6. When the volume ratio of the polyamide resin and the other resin in the split composite fiber (B) is less than 1/9, the content of the polyamide resin tends to decrease, and the liquid residue on the object tends to increase. When the volume ratio exceeds 9/1, the content of the polyamide resin is increased, and the fiber productivity may be reduced.

  The fineness of the split-type conjugate fiber (B) may be appropriately set according to the fineness of the ultrafine fiber (b) to be obtained, but is preferably in the range of 0.5 dtex to 5 dtex. The lower limit of the fineness of the more preferable split type composite fiber (B) is 1 dtex. The upper limit of the fineness of the more preferable split type composite fiber (B) is 4.4 dtex. If the fineness of the split-type conjugate fiber (B) is less than 0.5 dtex, the fiber productivity may be reduced. If the fineness of the split-type composite fiber (B) exceeds 5 dtex, it is necessary to increase the number of splits to obtain the ultrafine fiber (b), and the splittability may be lowered. Moreover, it is preferable that the division | segmentation number of a split type composite fiber (B) exists in the range of 4 or more and 32 or less.

Further, the split type composite fiber (B) is a fiber having a web shrinkage rate in the range of 20% to 60% obtained by the following method (hereinafter referred to as heat shrinkable split type composite fiber). preferable.
[Web shrinkage]
A web having a basis weight of 120 g / m ² is formed from the split type composite fibers (B), a water stream is jetted onto the web, and a hydroentanglement treatment is performed to adjust the split ratio of the split type composite fibers (B) to 60% or more. The area shrinkage rate when immersed in warm water at 70 ° C. for 25 seconds.
By setting the web shrinkage rate within the above range, the surface of the nonwoven fabric can be made denser by the action of the shrinkage, and not only the liquid droplets are reduced to reduce the liquid residue but also the wiping property is improved. Because you can. Furthermore, when the difference in shrinkage between two or more types of resin components constituting the split-type conjugate fiber (B) is provided, the splitability of the split-type conjugate fiber (B) can be promoted by the action of shrinkage. Similar effects can be obtained. The heat-shrinkable split composite fiber satisfying the web shrinkage can be obtained, for example, by drawing a filament compositely spun into a split mold with a combination of polyamide resin and polyester resin by 2.5 times or less. .

  The fiber layer containing the ultrafine fiber (va) preferably contains 20 mass% or more of the ultrafine fiber (va) in the fiber layer. A more preferable lower limit of the content of the ultrafine fiber (va) is 30 mass%. The ultrafine fiber (va) may be 100 mass%, but a preferable upper limit of the content of the ultrafine fiber (va) is 80 mass%. A more preferable upper limit of the content of the ultrafine fiber (va) is 60 mass%. When the amount of extra fine fibers (va) decreases, the amount of liquid remaining on the target surface tends to increase.

  The fiber layer containing the ultrafine fibers (va) may contain fibers other than the ultrafine fibers (va). Examples of fibers other than ultrafine fibers (va) include natural fibers such as cotton, pulp and hemp, recycled fibers such as viscose rayon, solvent-spun rayon, and cupra, polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, and polybutylene succin. Examples thereof include polyester fibers such as nates, polyamide fibers such as nylon 6 and nylon 66, polyolefin fibers such as polyethylene and polypropylene, and acrylic fibers. However, if the fineness of the fibers other than the ultrafine fibers (va) becomes too large, there is a large amount of liquid remaining on the target surface, and the wiping property may be lowered. Therefore, the fineness is preferably 2.5 dtex or less. Moreover, since the ultrafine fiber (va) has an appropriate wettability, and excessive wettability is imparted to the fiber layer, the liquid residue on the target surface increases, so that the natural fiber and the regenerated fiber are contained. In the case, it is good to make it 30 mass% or less.

  When the ultrafine fiber (va) is a fiber obtained by dividing and expressing the split-type composite fiber (VA), the content of the ultrafine fiber (va) is determined by the split ratio and mass ratio (volume ratio) of the split-type composite fiber (VA). ). The splitting ratio of the split-type composite fiber (VA) is preferably 30% or more. A more preferable lower limit of the division ratio is 60% or more. When the splitting ratio of the split-type composite fiber (VA) is less than 30%, not only the content of the ultrafine fiber (va) is decreased, but also the content of the unsplit split-type composite fiber (VA) is increased. This is because the amount of liquid remaining on the target surface tends to increase. As described above, in the present invention, the fiber group constituting the fiber layer varies depending on the split ratio of the split-type conjugate fiber (VA). For example, if the split ratio is 100%, it is composed of two types of ultrafine fibers (va) and ultrafine fibers composed of a resin other than the modified vinyl alcohol resin, and if the split ratio is less than 100%, In addition to the ultrafine fibers composed of a resin other than the ultrafine fibers (va) and the modified vinyl alcohol resin, a fiber layer in which split-type composite fibers (VA) and / or undivided split-type composite fibers (VA) are mixed. It becomes.

  The split composite fiber (VA) is preferably contained in the fiber layer by 60 mass% or more. The minimum of content of a more preferable split type composite fiber (VA) is 80 mass%. Most preferably, a fiber layer is comprised only by a split type composite fiber (VA). This is because if the content of the split-type composite fiber (VA) is less than 60 mass%, the content of the ultrafine fiber (va) decreases even if the split-type composite fiber (VA) is divided and expressed.

  Examples of the form of the fiber layer containing the ultrafine fiber (va) include a card web, an air lay web, a wet papermaking web, a spunbond web, and a melt blow web. Considering the entanglement property when the fiber layer containing the ultrafine fiber (va) and the fiber layer containing the ultrafine fiber (b) are hydroentangled, it is preferably a card web.

The basis weight of the fiber layer containing the ultrafine fibers (va) is preferably in the range of 8 g / m ² or more and 50 g / m ² or less. A more preferred lower limit of basis weight is 10 g / m ² . A more preferable upper limit of the basis weight is 25 g / m ² . This is because if the basis weight of the fiber layer containing the ultrafine fibers (va) is less than 8 g / m ² , the liquid residue on the target surface tends to increase. When the basis weight of the fiber layer containing the ultrafine fibers (va) exceeds 50 g / m ² , the handleability may be lowered when a wiper is obtained.

  Next, the fiber layer containing the synthetic fiber preferably contains an ultrafine fiber (b), and the ultrafine fiber (b) is preferably contained in an amount of 10 mass% or more in the fiber layer. A more preferable lower limit of the content of the ultrafine fiber (b) is 15 mass%. When the ultrafine fiber (b) decreases, the liquid remaining on the target surface tends to increase.

  The fiber layer containing the ultrafine fiber (b) may contain fibers other than the ultrafine fiber (b). Examples of fibers other than the ultrafine fibers (b) include natural fibers such as cotton, pulp and hemp, recycled fibers such as viscose rayon, solvent-spun rayon, and cupra, polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, and polybutylene succin. Examples thereof include polyester fibers such as nates, polyamide fibers such as nylon 6 and nylon 66, polyolefin fibers such as polyethylene and polypropylene, and acrylic fibers. However, if the fineness of the fibers other than the ultrafine fibers (b) becomes too large, there is a large amount of liquid remaining on the target surface and the wiping property may be inferior. Therefore, the fineness is preferably 5 dtex or less. In addition, when excessive wettability is imparted to the fiber layer, the liquid residue on the target surface increases, and therefore when the natural fiber and the regenerated fiber are contained, the content is preferably 30 mass% or less.

  When the ultrafine fiber (b) is a fiber in which the split type composite fiber (B) is divided and expressed, the content of the ultrafine fiber (b) is the split ratio and mass ratio (volume ratio) of the split type composite fiber (B). ). The split ratio of the split composite fiber (B) is preferably 10% or more. A more preferable lower limit of the division ratio is 50%. When the splitting rate of the split-type conjugate fiber (B) is less than 10%, not only the content of the ultrafine fiber (b) is decreased, but also the content of the undivided split-type conjugate fiber (B) is increased. This is because the liquid remaining on the target surface may increase. As described above, in the present invention, the fiber group constituting the fiber layer varies depending on the split ratio of the split composite fiber (B). For example, if the split ratio is 100%, the fiber layer is composed of ultrafine fibers (b) composed of two or more kinds of resins, and if the split ratio is less than 100%, the ultrafine fibers (b) In addition, a fiber layer in which the split-type composite fibers (B) and / or the unsplit split-type composite fibers (B) are mixed.

  The split composite fiber (B) is preferably contained in the fiber layer by 60 mass% or more. The minimum of content of a more preferable split type composite fiber (B) is 70 mass%. Most preferably, a fiber layer is comprised only by a split type composite fiber (B). This is because if the content of the split-type composite fiber (B) is less than 60 mass%, the content of the ultrafine fiber (b) decreases even if the split-type composite fiber (B) is expressed in a split manner.

  Examples of the form of the fiber layer containing the synthetic fiber include a card web, an air lay web, a wet papermaking web, a spunbond web, and a melt blow web. In consideration of the confounding property when the fiber layer containing the ultrafine fiber (b) and the fiber layer containing the ultrafine fiber (va) are hydroentangled, a card web is preferable.

The basis weight of the fiber layer containing the synthetic fiber is preferably in the range of 6 g / m ^{2 to} 40 g / m ² . A more preferred lower limit of basis weight is 10 g / m ² . A more preferable upper limit of the basis weight is 30 g / m ² . This is because if the basis weight of the fiber layer containing the ultrafine fiber (b) is less than 6 g / m ² , the liquid residue on the target surface tends to increase. When the basis weight of the fiber layer containing the ultrafine fiber (b) exceeds 40 g / m ² , the ultrafine fiber (va) may not be entangled near the surface of the nonwoven fabric even if hydroentangled.

  The lamination ratio (mass ratio) of the fiber layer containing the ultrafine fiber (va) and the fiber layer containing the ultrafine fiber (b) laminated on both surfaces of the fiber layer is the ultrafine fiber relative to the total mass of the laminated nonwoven fabric. When the fiber layer containing (va) is expressed by mass, it is preferably in the range of 25 mass% or more and 80 mass% or less. A more preferable lower limit of the mass ratio is 30 mass%. A more preferable upper limit of the mass ratio is 60 mass%. When the mass ratio of the fiber layer containing the ultrafine fibers (va) is less than 25 mass%, the liquid residue on the target surface tends to increase. This is because if the mass ratio of the fiber layer containing the ultrafine fibers (va) exceeds 80 mass%, the handleability may be lowered when the wiper is used.

The basis weight of the laminated nonwoven fabric for wipers of the present invention is preferably in the range of 20 g / m ^{2 to} 120 g / m ² . A more preferable lower limit of the basis weight is 30 g / m ² . A more preferable upper limit of the basis weight is 90 g / m ² . If the basis weight of the laminated nonwoven fabric for wipers is less than 20 g / m ² , the texture of the nonwoven fabric tends to decrease. If the basis weight exceeds 120 g / m ² , the handleability may be lowered when used as a wiper, and the cost is increased.

  Next, an example of the manufacturing method of the laminated nonwoven fabric for wipers of this invention is demonstrated. First, the ultrafine fiber (va) or a fiber that expresses the ultrafine fiber (va) later is prepared, and a fiber web having the above-described form is formed. On the other hand, the synthetic fiber, preferably the ultrafine fiber (b) or the fiber that expresses the ultrafine fiber (b) later is prepared, and the fiber web having the above-described form is formed. Next, synthetic fibers, preferably ultrafine fibers (b) or fibers that express the ultrafine fibers (b) later are formed on both sides of the fiber web containing the ultrafine fibers (va) or fibers that express the ultrafine fibers (va). Laminated fiber webs are laminated (laminated web). And the said laminated web is mounted on a web conveyance support body, a water flow is injected on the single side | surface or both surfaces of a laminated web, and a hydroentanglement process is performed. Hydroentanglement treatment conditions can be appropriately set according to the basis weight of the laminated nonwoven fabric to be obtained. For example, from a nozzle provided with orifices having a hole diameter of 0.05 mm or more and 0.5 mm or less at intervals of 0.5 mm or more and 1.5 mm or less, a water flow with a water pressure of 3 MPa or more and 15 MPa or less is respectively applied from the front and back sides of the laminated web. It is good to inject 4 times. In particular, when a split type composite fiber is contained in the laminated web, the water pressure can be adjusted in consideration of splitting properties, and the water pressure is preferably 6 MPa or more and 12 MPa or less.

  The hydroentangled laminated web is dried to remove moisture. If necessary, the laminated web may be mixed with heat-adhesive binder fibers. In this case, heat treatment may be performed at a temperature at which only the heat-adhesive binder fibers are melted after drying or simultaneously with drying. The heat-adhesive binder fiber preferably has a fineness of 4 dtex or less. However, it is preferable that it is the range which does not exceed 30 mass% as the whole laminated nonwoven fabric.

  The ultrafine fiber (b) is a fiber obtained by dividing and expressing the split composite fiber (B), and when the split composite fiber (B) is the heat-shrinkable split composite fiber, modified vinyl A fiber layer containing a heat-shrinkable split-type composite fiber is laminated on both sides of a fiber layer containing a split-type composite fiber (VA) containing at least one component of an alcohol resin (laminated web), and modified vinyl alcohol by hydroentanglement treatment It is good to heat-process so that an area shrinkage rate may become 10% or less, after dividing and expressing the ultrafine fiber (va) containing, and integrating a laminated web. A more preferable upper limit of the area shrinkage rate is 8%. A more preferable upper limit of the area shrinkage rate is 6%. If the area shrinkage rate exceeds 10%, the surface of the nonwoven fabric tends to be uneven due to the shrinking action of the heat-shrinkable split composite fibers, and there is a possibility that the liquid residue on the target surface will increase. As a heat treatment method for adjusting the area shrinkage rate to 10% or less, for example, the shrinkage in the width direction of the nonwoven fabric is set to a desired range with a pin tenter, a clip tenter, etc., and the roll speed is adjusted to adjust the roll direction in the machine direction of the nonwoven fabric. It can be obtained by adjusting the shrinkage to a desired range.

  The laminated nonwoven fabric for wipers of the present invention thus obtained can be used as a dry wiper by attaching liquid paraffin or the like as necessary.

  Moreover, the laminated nonwoven fabric for wipers of the present invention can be used as a wet wiper by adhering with a wetting agent such as water, alcohol, surfactant, cosmetics, etc., if necessary, by impregnation, spraying, coating or the like. When used as a wet wiper, it is preferable that 100 parts by mass of the laminated nonwoven fabric contain a wetting agent in the range of 50 parts by mass to 300 parts by mass.

  Hereinafter, the laminated nonwoven fabric for wipers of the present invention will be described in detail with reference to examples. The web shrinkage rate, thickness, tensile strength, breaking elongation, division rate, nonwoven fabric area shrinkage rate, wiping property, liquid residue property, and oily soil wiping property were measured as follows.

[Web shrinkage]
A web having a basis weight of 120 g / m ² is formed from the split composite fiber (B), and a water stream is jetted onto the web to adjust the split ratio of the split composite fiber (B) to 60% or more. Thus, a web before shrinkage treatment was obtained. Specifically, a web is placed on a carrier support and conveyed at a speed of 4 m / min, and a columnar water stream is supplied at a water pressure of 5 MPa from a nozzle provided with orifices having a hole diameter of 0.08 mm at intervals of 0.6 mm. After jetting twice at 8 MPa once, the opposite surface was jetted twice at a water pressure of 8 MPa and hydroentangled, and the splitting rate of the split-type conjugate fiber (B) was adjusted to 80%.
The web before shrinkage treatment was cut into a length of 15 cm × width of 15 cm and immersed in warm water at 70 ° C. for 25 seconds to measure the size of the web (length TA, width WA), and calculated from the following formula. .
Web shrinkage (%) = {(15 × 15−TA × WA) / 15 × 15} × 100

[Thickness]
Using a thickness measuring machine (trade name: THICKNESS GAUGE model CR-60A, manufactured by Daiei Kagaku Seiki Seisakusho Co., Ltd.), the measurement was performed with a load of 2.94 cN per 1 cm ^{2 of} the sample.

[Tensile strength, elongation at break]
In accordance with JIS-L-1096, a test piece having a width of 5 cm and a length of 15 cm is gripped at a spacing of 10 cm, and tensioned using a constant speed extension type tensile tester (trade name: Tensilon, manufactured by Orientec Co., Ltd.). The sample was stretched at a speed of 20 cm / min, and the load value and elongation rate at the time of cutting the test piece were taken as tensile strength and breaking elongation, respectively.

[Split rate]
The non-woven fabric is bundled so that the machine direction is a cross-section so that no space is generated, is magnified 300 times with an electron microscope, and is arbitrarily photographed at three locations, and the number of single fibers divided in the photograph is By dividing by the total number of single fibers and the number of partially divided fibers and undivided fibers, a value multiplied by 100 was taken as the division ratio.

[Area shrinkage of nonwoven fabric]
A laminated web described later was cut into 15 cm × 15 cm, and the shrinkage rate when heat-treated under the conditions described in the examples was measured.

[Wipeability]
A laminated nonwoven fabric cut to 30 cm in the longitudinal direction (machine direction of the nonwoven fabric) and 21 cm in the lateral direction (width direction of the nonwoven fabric) is used as a sample, and 200 parts by mass of water is impregnated with 100 parts by mass of the sample to be wet. A wiper was produced. The wet wiper was folded in four, and the wiping situation after three reciprocations of a 30 cm × 50 cm glass surface to which muddy soil had previously been attached was visually observed, and four of ◎, ○, Δ, and × were observed. Rated by stage. The evaluation criteria were as follows.
(Double-circle): All dirt fell off neatly.
○: Dirt was almost removed.
Δ: Some dirt remains.
X: There is much dirt residue.

[Liquid residue]
The wet wiper is folded in four, a 5 cc water drop is dropped on a glass surface of 30 cm × 50 cm with a dropper, and the water drop remaining on the glass surface after reciprocating the wet drop with the wet wiper 3 times. The state was visually observed and evaluated according to the following five grades. The average grade when evaluated with n = 2 was defined as liquid residue.
First grade: There are many remaining liquids, water droplets are quite large, and scales are noticeable when dried.
Second grade: Liquid remains, water droplets are large, and scales can be confirmed when dried.
Grade 3: There are liquid residue in some places, and water droplets are small, but some water scale can be confirmed when dried.
Grade 4: There is a little liquid residue, but water droplets are small, and scale does not stand out even when dried.
Grade 5: There is no liquid residue and there is no scale even when dried.

[Observation of oil stains]
(1) Wiping rate A. The laminated nonwoven fabric for wiper (dry) was cut into a length of 11 cm and a width of 7 cm to prepare a sample.
B. Draw a 20cm vertical x 7cm horizontal frame with oil-based ink on an acrylic plastic plate (mass a), and apply the following model sebum (approx. 0.2g) uniformly with a 45mm wide brush (mass) b).
C. Mount the sample on a polyethylene sponge pad (Yamazaki Sangyo Co., Ltd., glass wiper) with a length of 5cm x width 7cm and a thickness of 2mm. Place a load of 500g on the sponge pad and place it in the frame so that the directions match each other. Set.
D. Sebum was wiped off while slowly pulling the sponge pad in the vertical direction (within a 20 cm frame).
E. The mass (c) of the acrylic plastic plate after wiping was measured, and the wiping rate was calculated by the following formula.
Wiping rate (%) = {1− (c−a) / (b−a)} × 100

(2) Number of wipes The laminated nonwoven fabric for wiper (dry) was cut into a length of 11 cm and a width of 7 cm to prepare a sample.
B. One drop (about 0.04 ml) of the model sebum shown below was dropped onto a mirror surface having a size of 30 cm in length and 60 cm in width with a dropper.
C. When the sample is folded in four and the mirror surface is pressed with two fingers, the sample folded in four in the vertical direction is moved and reciprocated until the sebum is removed. The number of times was defined as the number of times of wiping.

(3) Model sebum The composition of model sebum is as follows.
A. Squalane 16.1%
B. Trio Rain 31.5%
C. Oleic acid 46.0%
D. Liquid paraffin 6.7%

[Example 1]
As a split type composite fiber (VA) containing a modified vinyl alcohol resin, the first component (modified vinyl alcohol resin component) is an ethylene-vinyl alcohol copolymer (ethylene content 38 mol%), and the second component is a polypropylene resin. A 16-split composite fiber (manufactured by Daiwabo Co., Ltd., trade name: DF-2) having a fiber cross section of FIG. 1B having a fineness of 3.3 dtex and a fiber length of 45 mm was prepared.

  As the split type composite fiber (B), the first component is nylon 6 resin and the second component is polyethylene terephthalate resin, and the fiber cross section of FIG. 1B having a fineness of 4.4 dtex and a fiber length of 45 mm is shown. A heat-shrinkable conjugate fiber (Daiwabo Co., Ltd., trade name: DFH-5) was used.

Subsequently, the parallel card web (VA) which consists of a split type composite fiber (VA) with a fabric weight of 12.5g / m < ² > was produced using the parallel card machine. On the other hand, the parallel card web (B) which consists of a split type composite fiber (B) with a fabric weight of 18.75 g / m < ² > was produced using the parallel card machine. The laminated web was laminated so that the parallel card web (B) was disposed on both sides of the parallel card web (VA) to obtain a laminated web having a three-layer structure.

  The laminated web was placed on a plain weave carrier having a warp wire diameter of 0.2 mm and a weft wire diameter of 0.2 mm, and an orifice having a pore diameter of 0.12 mm was placed on the laminated web with a 1 mm orifice. Water flow entanglement treatment is performed by injecting a water flow with a water pressure of 2.5 MPa twice from nozzles aligned in the width direction of the laminated web at intervals, turning the laminated web upside down and injecting a water flow with water pressure of 4 MPa from the same nozzle twice. And laminated the laminated web.

  Next, the hydroentangled laminated web is dried using a hot air processing machine set at a temperature of 140 ° C. while holding both ends in the length direction of the laminated web and freeing both ends in the width direction. At the same time, a fiber layer containing ultrafine synthetic fiber (b) made of nylon 6 and polyethylene terephthalate was laminated on both sides of the fiber layer containing ultrafine fiber (va) made of ethylene-vinyl alcohol copolymer. A laminated nonwoven fabric for wipers according to the present invention was obtained.

[Example 2]
As the split type composite fiber (B), the first component is made of nylon 6 resin and the second component is made of polyethylene terephthalate resin. The split type composite fiber (B) is a 16 split type having a fiber cross section of FIG. A laminated web subjected to hydroentanglement treatment in the same manner as in Example 1 was obtained except that composite fibers (manufactured by Daiwabo Co., Ltd., trade name: DFF-5) were used. Next, the hydroentangled laminated web was heat-treated in the same manner as in Example 1, and nylon 6 and polyethylene terephthalate were formed on both sides of the fiber layer containing ultrafine fibers (va) made of an ethylene-vinyl alcohol copolymer. A laminated nonwoven fabric for wipers according to the present invention in which a fiber layer containing ultrafine synthetic fibers (b) made of

[Example 3]
As the split type composite fiber (B), the first component is nylon 6 resin and the second component is polyethylene terephthalate resin, the fineness is 3.3 dtex, the fiber length is 45 mm and the fiber cross section of FIG. A laminated web subjected to hydroentanglement treatment in the same manner as in Example 1 was obtained except that a composite fiber (Daiwabo Co., Ltd., trade name: DF-5) was used. Next, the hydroentangled laminated web was heat-treated in the same manner as in Example 1, and nylon 6 and polyethylene terephthalate were formed on both sides of the fiber layer containing ultrafine fibers (va) made of an ethylene-vinyl alcohol copolymer. A laminated nonwoven fabric for wipers according to the present invention in which a fiber layer containing ultrafine synthetic fibers (b) made of

[Comparative Example 1]
Example 1 was used in the same manner as in Example 1 except that rayon fibers having a fineness of 1.7 dtex and a fiber length of 44 mm (trade name: Corona, manufactured by Daiwabo Rayon Co., Ltd.) were used instead of the split composite fibers (VA). A laminated nonwoven fabric was produced.

[Comparative Example 2]
Example 1 except that polyethylene terephthalate fiber (PET) having a fineness of 1.1 dtex and a fiber length of 51 mm (trade name: Tetoron) was used instead of the split composite fiber (VA). A laminated nonwoven fabric was produced in the same manner.
The physical properties of Examples 1 to 3 and Comparative Examples 1 and 2 are shown in Table 1.

  The laminated nonwoven fabrics for wipers of Examples 1 to 3 all had little liquid remaining on the target surface and were excellent in wiping properties. In particular, the laminated nonwoven fabric of Example 1 was subjected to hydroentanglement treatment using a split-type composite fiber having shrinkability, and then adjusted to shrink to 10% or less in the length direction and width direction of the nonwoven fabric. The liquid remaining on the surface and the wiping property were excellent. Further, in the laminated nonwoven fabrics for wipers of Examples 1 to 3, ultrafine fibers made of an ethylene-vinyl alcohol copolymer constituting the intermediate layer were present not only inside the nonwoven fabric but also near the surface by hydroentanglement treatment. For that reason, it was excellent in wiping and retaining properties against oily dirt.

  On the other hand, in the laminated nonwoven fabric of Comparative Example 1, the rayon fibers constituting the intermediate layer were also present near the surface of the nonwoven fabric by hydroentanglement treatment. The water remained on the target surface because of the remaining moisture in the rayon fiber, and the wiping property was not sufficient. Furthermore, in the laminated nonwoven fabric of Comparative Example 2, the polyethylene terephthalate fibers constituting the intermediate layer were also present near the surface of the nonwoven fabric by hydroentanglement treatment. For this reason, the effect of sucking water on the target surface is small, the amount of liquid remaining on the target surface is large, and wiping property is not sufficient.

  The laminated nonwoven fabric for wipers of the present invention can be suitably used for OA equipment such as a display, objectives such as glasses, automobiles, kitchens, shoes, and wipers that wipe off a target surface with dirt and oily dirt adhering to people. .

An example of the fiber cross section in the split type composite fiber of this invention is shown.

Explanation of symbols

1 1st component 2 2nd component

Claims (12)

Ultrafine fiber (va) having a fineness of 0.9 dtex or less and a modified vinyl alcohol resin which is a copolymer of an α-olefin selected from the group of ethylene, propylene, 1-butene, isoprene and 1-hexene and vinyl alcohol A laminated nonwoven fabric for wipers in which fiber layers containing ultrafine fibers (b) having a fineness of 0.9 dtex or less are laminated on both sides of a fiber layer containing ) and integrated by hydroentanglement.   The laminated nonwoven fabric for wiper according to claim 1, wherein the ultrafine fiber (va) is a fiber obtained by dividing and expressing a split type composite fiber (VA) containing a modified vinyl alcohol resin as at least one component.   The laminated nonwoven fabric for wiper according to claim 2, wherein the split type composite fiber (VA) is a split type composite fiber having at least two components of a modified vinyl alcohol resin and a polyolefin resin.   The laminated nonwoven fabric for wiper according to any one of claims 1 to 3, wherein the modified vinyl alcohol resin is an ethylene-vinyl alcohol copolymer having an ethylene content in a range of 30 mol% to 50 mol%.   The laminated nonwoven fabric for wiper according to claim 4, wherein the ultrafine fiber (b) is a fiber containing a polyamide resin.   The laminated nonwoven fabric for wiper according to claim 4 or 5, wherein the ultrafine fiber (b) is a fiber obtained by dividing and expressing the split type composite fiber (B).   The laminated nonwoven fabric for wiper according to claim 6, wherein the split type composite fiber (B) is a split type composite fiber having at least two components of a polyamide resin and a polyester resin. The split-type composite fiber (B) is a fiber having a web shrinkage rate in the range of 20% to 60% obtained by the following method (hereinafter referred to as heat-shrinkable split-type composite fiber). The laminated nonwoven fabric for wipers according to 7.
[Web shrinkage]
A web having a weight per unit area of 120 g / m ² formed from the split composite fiber (B), jetted with a water stream and subjected to hydroentanglement to adjust the split ratio of the split composite fiber (B) to 60% or more. The area shrinkage rate when immersed in warm water at 70 ° C. for 25 seconds.   The said laminated nonwoven fabric is formed by laminating a fiber layer containing 10 mass% or more of ultrafine fibers (b) on both sides of a fiber layer containing 20 mass% or more of ultrafine fibers (va). Laminated nonwoven fabric for wipers.   The laminated nonwoven fabric is a nonwoven fabric obtained by laminating a fiber layer containing 60 mass% or more of heat-shrinkable split composite fibers on both sides of a fiber layer containing 60 mass% or more of splittable composite fibers (VA). The laminated nonwoven fabric for wipers in any one of -9. Includes split type composite fibers (VA) containing at least one component of a modified vinyl alcohol resin that is a copolymer of an α-olefin and vinyl alcohol selected from the group consisting of ethylene, propylene, 1-butene, isoprene, and 1-hexene A fiber web containing heat-shrinkable split-type composite fibers is laminated on both sides of the fiber web (hereinafter referred to as “laminated web”), and ultrafine fibers (va) containing a modified vinyl alcohol resin are divided and expressed by hydroentanglement treatment, and the laminated web. A method for producing a laminated nonwoven fabric for wipers, in which heat treatment is performed so that the area shrinkage rate is 10% or less after integrating the substrate.   The range of 50 to 300 parts by mass of a wetting agent to 100 parts by mass of the laminated nonwoven fabric for wipers according to any one of claims 1 to 10 or the laminated nonwoven fabric for wipers obtained by the production method according to claim 11. A wet wiper that is contained inside.

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