JP2008208492A - Moisture-retaining nonwoven fabric and its production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a moisture-retaining nonwoven fabric whose surface is uneven, and which has improved skin touch such as puffy touch and softness, improved wiping properties including water absorbability and a water retaining ability, and has an enhanced moisture-retaining touch to skin. <P>SOLUTION: This moisture-retaining nonwoven fabric containing a water-soluble component in an amount of ≥1% based on the weight of nonwoven fabric base paper. In the nonwoven fabric, an equilibrium moisture regain-increasing rate on the comparison of the equilibrium moisture regain of the moisture-retaining nonwoven fabric with an equilibrium moisture regain on the removal of the water-soluble component from the moisture-retaining nonwoven fabric is ≥0.5%, and the surface of the moisture-retaining nonwoven fabric has unevenness having a difference in height of ≥100 μm. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a moisturizing nonwoven fabric having moisturizing properties by containing a moisturizing component and further having irregularities on the surface and a method for producing the same.

Conventionally, some sanitary paper products such as toilet paper have an uneven pattern by embossing to increase the bulk and water absorption. Further, as a technique for forming irregularities on the surface of a nonwoven fabric, there is a process of blending thermoplastic fibers and heat-sealing to form an irregular pattern (Patent Document 1).
JP 2006-104629 A

  A moisturizing non-woven fabric product is a product in which a moisturizing component is contained in a non-woven fabric to be a base fabric, and the contained moisturizing component lowers the bulk and lowers the water retaining capacity of the base fabric non-woven fabric. Moreover, in order to increase the affinity with the moisturizing component and the moist feeling due to the moisturizing component, it is preferable to blend pulp fibers that are hydrophilic fibers into the nonwoven fabric, but the spunlace method as described in Patent Document 1 above, etc. In the processing method using water, hydrogen bonds are formed between the fibers, and the bulk may decrease or the texture may become hard.

  Therefore, the present invention eliminates defects due to the inclusion of moisturizing ingredients by forming irregularities on the surface of the moisturizing nonwoven fabric, and improves the wiping properties including soft feeling, softness and the like, as well as water absorption and water retention. It is intended to enhance the moisturizing feeling on the skin.

  Furthermore, the present invention intends to provide a method for producing a moisturizing nonwoven fabric having irregularities on the surface that is simple and excellent in workability.

  The moisturizing nonwoven fabric according to the present invention contains 1% or more of a water-soluble component with respect to the weight of the nonwoven fabric base sheet, and has an equilibrium moisture content of the moisturizing nonwoven fabric and an equilibrium moisture content when the water-soluble component is removed from the moisturizing nonwoven fabric. It is assumed that the moisture retention nonwoven fabric has an equilibrium moisture content increase rate of 0.5% or more when compared, and the surface of the moisture retention nonwoven fabric has irregularities with an elevation difference of 100 μm or more.

  The moisturizing nonwoven fabric referred to in the present invention is a nonwoven fabric containing a moisturizing component. The water-soluble component is a component (excluding fallen fibers) that is washed away when the moisturizing nonwoven fabric is washed with distilled water at 60 ° C. Water-soluble ingredients include water-soluble and water-dispersible ingredients by solubilizing and emulsifying a moisturizing ingredient, moisture retained when the moisturizing ingredient is in equilibrium with the atmosphere, and a lipophilic substance with a surfactant. Etc. are included.

  Water-soluble component content is 1-250% with respect to the weight of a nonwoven fabric base paper, Preferably it is 5-150%, More preferably, it is 10-100%. The water-soluble component content can be controlled by the amount of the moisturizing liquid applied to the nonwoven fabric base paper. If the water-soluble component content is less than 1%, the nonwoven fabric is felt hard. If it exceeds 250%, there is a sticky feeling. 10% to 50% is most preferable when the moisturizing nonwoven fabric is desired to be soft and smooth and smooth. When the moisturizing nonwoven fabric is moist and moisturizing effect is required, 50-100% is most preferable.

  The equilibrium moisture content increase rate when comparing the equilibrium moisture content of the moisturizing nonwoven fabric and the equilibrium moisture content when the water-soluble component is removed from the moisturizing nonwoven fabric is preferably 0.5 to 40%, more preferably 1.0 to 20%. 1.0% to 3.0% is most preferable when the moisturizing nonwoven fabric is required to be soft and smooth and smooth. When the moisturizing nonwoven fabric is moist and the moisturizing effect on the skin is required, 3.0 to 10% is most preferable. When the rate of increase in the equilibrium moisture content is 0.5% or less, the properties such as softness and moist feeling of the moisturizing nonwoven fabric are insufficient. When the equilibrium moisture content increase rate is 40% or more, the sticky feeling becomes strong, which is not preferable.

  The unevenness on the surface of the moisturizing nonwoven fabric has a height difference of 100 μm or more, preferably 200 μm or more, and more preferably 300 μm or more. If there are irregularities on the surface of the moisturizing nonwoven fabric, it becomes bulky and becomes a moisturizing nonwoven fabric with a soft touch. Furthermore, water absorption and water retention improve by becoming bulky. When a moisturizing nonwoven fabric with irregularities on the surface is used as a wiper for wiping away dirt on the skin, the wipeability of dirt is improved due to the effect of scraping off dirt due to the convex portions on the surface and the effect of retaining dirt due to the concave portions on the surface. At the same time, since the convex portion of the surface is firmly in contact with the skin, the moisturizing liquid contained in the moisturizing nonwoven fabric is easily transferred to the skin, and the moisturizing feeling of the skin is also improved. If the unevenness on the surface of the moisturizing nonwoven fabric has an elevation difference of 100 μm or less, these effects are difficult to obtain. However, the unevenness on the surface of the moisturizing nonwoven fabric does not include fuzz on the surface of the moisturizing nonwoven fabric.

  As a means for forming irregularities on the surface of the moisturizing nonwoven fabric, a means for forming irregularities by forming a portion where the fibers are partially crushed in the moisturizing nonwoven fabric as in the embossing method, and a moisturizing effect as in a manufacturing method using the hydroentanglement method. There is a means for forming irregularities by making a part of the nonwoven fabric with a small number of fibers. Either means may be used in the present invention.

The moisturizing nonwoven fabric having irregularities on the surface of the moisturizing nonwoven fabric according to the present invention has irregularities on the surface of the moisturizing nonwoven fabric in the form of dots, and the number per unit area is 0.6 to 50 / cm ² . The number of dots per unit area is 0.6 to 50 / cm ² , preferably 1 to 30 / cm ² , and more preferably 3 to 20 / cm ² . When the number of dots per unit area is less than 0.6 / cm ^2, it is difficult to obtain effects such as a soft feeling due to surface irregularities, improved wiping of dirt, and improved moisturizing feeling on the skin. When the number of dots per unit area is more than 50 / cm ² , the unevenness on the surface of the moisturizing nonwoven fabric becomes unclear, and it is difficult to obtain the above effect.

Furthermore, the moisturizing nonwoven fabric having unevenness on the surface of the moisturizing nonwoven fabric according to the present invention is such that the unevenness on the surface of the moisturizing nonwoven fabric is striped, and the pitch between stripes is 1.1 mm or more. The pitch between stripes is 1.1 mm or more, preferably 2 to 15 mm, more preferably 3 to 10 mm. When the pitch between stripes is 1.1 mm or less, the above effect is hardly obtained.
Furthermore, the moisturizing nonwoven fabric having irregularities on the surface of the moisturizing nonwoven fabric according to the present invention has mesh-shaped irregularities on the surface of the moisturizing nonwoven fabric, and the mesh size is 2 to 23 mesh. The mesh size is 2 to 23 mesh, preferably 5 to 20 mesh. If the mesh spacing is larger than 2 mesh or smaller than 23 mesh, the moisturizing non-woven fabric is difficult to be bulky, so that the effect of improving the soft feeling, water absorption, water retention, dirt wiping property, moisturizing feeling, etc. is obtained. It's hard to be done.

  Furthermore, in the moisturizing nonwoven fabric having unevenness on the surface of the moisturizing nonwoven fabric according to the present invention, the concave and convex portions on the surface of the moisturizing nonwoven fabric are through holes, and the short diameter of the through holes is 100 μm or more. The short diameter of the through hole means the length of the short diameter when the through hole is elliptical. When the through hole is rectangular, it means the length of the short side. When the recess is a through-hole, the unevenness becomes clear and the wiping property for dirt is particularly improved.

  It is a means for forming irregularities on the surface of the moisturizing nonwoven fabric, and as a manufacturing method for forming irregularities by forming a portion where fibers are partially crushed on the moisturizing nonwoven fabric, the irregularities on the surface of the moisturizing nonwoven fabric are formed by embossing.

  Furthermore, in the method for producing a moisturizing nonwoven fabric having irregularities on the surface of the moisturizing nonwoven fabric according to the present invention, the irregularities on the surface of the moisturizing nonwoven fabric are formed by embossing in a wet state. In a non-woven fabric containing pulp that is preferable as a base paper for a moisturizing non-woven fabric, hydrogen bonding between pulp fibers is loosened and easily deformed by making it wet. When embossed in this state, irregularities are clearly formed on the surface of the moisturizing nonwoven fabric. However, it is preferable to dry quickly because the unevenness tends to collapse when left in a wet state. By drying, hydrogen bonds are newly formed between the pulp fibers, and the unevenness is not easily crushed or deformed.

  Examples of embossed shapes include dot shapes, stripe shapes, and mesh shapes, but other shapes such as geometric shapes, characters, and illustrations may also be used. By doing so, the designability can be enhanced.

  The embossing may be performed before or after the moisturizing process. However, when the embossed non-woven fabric is moisturized, unevenness due to the embossing tends to become unclear, and therefore embossing is preferably performed after the moisturizing processing. It is more preferable to perform embossing immediately after the moisturizing process and dry quickly, since the same effect as embossing in a wet state can be obtained. Most preferably, the moisture content of the moisturizing liquid used at that time is set to be 1 to 40% higher than the equilibrium moisture content of the moisturizing liquid.

  It is a means to form unevenness on the surface of the moisturizing nonwoven fabric, and as a manufacturing method to form the unevenness by partially forming a portion with a small number of fibers in the moisturizing nonwoven fabric, a pattern is applied at the time of hydroentanglement treatment at the time of production of the spunlace nonwoven fabric. It is a method of performing moisturizing processing.

  The manufacturing method of the moisture retention nonwoven fabric which has an unevenness | corrugation in the moisture retention nonwoven fabric surface concerning this invention is a nonwoven fabric by which the nonwoven fabric was manufactured by the spunlace method, and the mesh of the conveyance belt used at the time of a hydroentanglement process is 2-23 mesh. When hydroentanglement processing is performed using a conveyance belt that satisfies this condition, the fibers constituting the nonwoven fabric are repelled by the high-pressure columnar flow at the position corresponding to the convex portion of the wire constituting the conveyance belt, and a recess is formed. Thus, a mesh-like nonwoven fabric having the same mesh size as that of the transport belt can be produced. When the water pressure of the high-pressure columnar flow is sufficiently high, a through hole is formed at that position. The mesh of the conveyor belt is 2 to 23 mesh, preferably 5 to 20 mesh. If the mesh interval of the conveying belt becomes larger than 2 meshes, the fibers flow together with water during the hydroentanglement process. When moisture retention is performed on the nonwoven fabric produced by this production method, a moisture retention nonwoven fabric having mesh-like irregularities on the surface of the moisture retention nonwoven fabric and a mesh size of 2 to 23 mesh is obtained.

  The method for producing a moisturizing nonwoven fabric having irregularities on the surface of the moisturizing nonwoven fabric according to the present invention is a nonwoven fabric in which the nonwoven fabric is produced by a spunlace method, and the nozzle pitch used during hydroentanglement processing is 1.1 mm or more. When moisturizing is performed on the nonwoven fabric produced by this manufacturing method, a moisturizing nonwoven fabric in which the unevenness on the surface of the moisture retaining nonwoven fabric is striped and the pitch between stripes is 1.1 mm or more is obtained. The nozzle pitch used in the hydroentanglement process is 1.1 mm or more, preferably 2 to 15 mm, more preferably 3 to 10 mm.

  The nozzle pitch in the hydroentanglement process is usually 0.5 to 1.0 mm. A non-woven fabric is produced using a water-entanglement nozzle with a nozzle pitch of 0.5 to 1.0 mm during the production of spunlace nonwoven fabric, and finally, a water-entanglement nozzle with a nozzle pitch of 1.1 mm or more is used to A production method that performs entanglement treatment is preferred. By doing so, the part which the high pressure columnar flow which arises from the water flow entanglement nozzle of 1.1 mm or more nozzle pitch forms a continuous recessed part part in a nonwoven fabric flow direction. Thereby, the nonwoven fabric which has the stripe-shaped unevenness | corrugation of the same space | interval as the nozzle pitch of 1.1 mm or more can be manufactured. In order to form the stripe-shaped irregularities clearly, it is preferable to use a conveyor belt having a mesh number of 23 mesh or more, preferably 50 mesh or more. When a moisturizing process is performed on a non-woven fabric having stripe-shaped unevenness, a moisturizing non-woven fabric having stripe-shaped unevenness on the surface of the moisturizing nonwoven fabric is obtained.

  Moreover, a pattern cylinder may be arrange | positioned between a hydroentanglement nozzle and a nonwoven fabric at the time of a hydroentanglement process, and an unevenness | corrugation may be formed in the nonwoven fabric surface. The pattern shape of the pattern cylinder may be a dot shape, a stripe shape, or a mesh shape. Other geometric patterns, characters, and illustrations may be used. In that case, the designability can be improved. When such a patterned nonwoven fabric with moisture is moisturized, a moisture-holding nonwoven fabric with patterned irregularities is obtained.

  Conventional nonwoven fabric manufacturing techniques can be employed for the production of the nonwoven fabric before carrying the water-soluble component, that is, the nonwoven fabric base paper.

  Specific examples include a spunlace method, a spunbond method, a wet method, an air laid method, a chemical bond method, and a melt blow method. These production methods can be combined to produce.

  The spunlace method is indispensable when forming irregularities on the nonwoven fabric surface by hydroentanglement treatment, but the spunlace method is a preferred manufacturing technique even when irregularities are formed on the nonwoven fabric surface by the embossing method. Among these, a spunlace nonwoven fabric containing cellulosic fibers such as pulp and rayon is more preferable because it has good water absorption and a moist feeling.

The basis weight of the nonwoven fabric base paper can be set to 20 to 100 g / m ² . When pliability, drapeability, etc. are important, such as the use of wiping fine parts such as around the eyes, it is preferably 30 to 60 g / m ² , more preferably 40 to 50 g / m ² . On the other hand, when high water absorption, strength, etc. are important, such as for wiping the entire body, it is 40 to 100 g / m ² , more preferably 50 to 80 g / m ² .

  The water-soluble component can be supported on the nonwoven fabric by applying a moisturizing liquid to the nonwoven fabric base paper. The moisturizing liquid can contain a moisturizing component, water, oils, a surfactant for dispersing the oils in the moisturizing liquid, and the like. If the coating is carried out with the moisture content in the moisturizing liquid adjusted to be close to the equilibrium moisture content of the moisturizing liquid, the drying and humidity conditioning steps after coating can be omitted, which is economical.

  Moisturizing ingredients are substances that have a high moisture retention capacity. Specific examples thereof include glycerin, diglycerin, polyglycerin, ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, 1,3-butylene glycol, sorbit, xylitol, and erythritol. , Mannitol, lactitol, oligosaccharide alcohol, maltitol, reduced starch hydrolyzate, fructose, glucose, oligosaccharide, trehalose, glycine betaine, pyrrolidone carboxylic acid, pyrrolidone carboxylate, hyaluronic acid, hyaluronate, lactic acid, lactate And urea.

  Glycerin is suitable in terms of hygroscopicity, cost, and safety. In addition, sorbitol has a lower hygroscopicity than glycerin, but has a high ability to retain the moisture once taken in, and when used in combination with glycerin, the effect of buffering the moisture change of the moisturizing nonwoven fabric accompanying the change in environmental humidity can be obtained.

  Specific examples of oils include hydrocarbons such as liquid paraffin and squalane, olive oil, camellia oil, castor oil, soybean oil, palm oil, beef tallow, tri (caprylic acid / capric acid) glycerin, glycerin tricaprylate, etc. Examples include fats and oils, ester oils such as isopropyl myristate, isopropyl palmitate, and cetyl octanoate.

  The more oils, the better the transferability to the skin.

  Moisture contained in the moisturizing nonwoven fabric is moisture retained by the moisture retention of the moisturizing component and the nonwoven fabric base paper. That is, it is moisture in equilibrium with moisture contained in the air in the environment where the moisturizing nonwoven fabric is placed. It is essentially different from a product such as wet tissue that contains 200% or more moisture with respect to the weight of the nonwoven fabric and requires a package that prevents drying. However, for the purpose of maintaining hygiene and maintaining a moist feeling, it is possible to perform sealed packaging, and further to package with a high or low moisture content. The moisture content of the packaged moisturizing nonwoven fabric is preferably an equilibrium moisture content at 23 ° C. + 40% or less, more preferably an equilibrium moisture content at 23 ° C. + 20% or less, and an equilibrium moisture content at 23 ° C. + 10%. Most preferably:

  The method of applying the moisturizing liquid to the non-woven base paper can be selected from ordinary coating methods such as gravure coating, spray coating, die coating and dipping. Although single-sided coating may be used, double-sided coating is preferable in order to make the front and back of the nonwoven fabric even.

  The moisturizing nonwoven fabric according to the present invention can improve the texture such as softness and softness by imparting irregularities to the surface of the moisturizing nonwoven fabric, and at the same time, water absorption, water retention, wiping properties, moisturizing feeling to the skin Can be increased.

  Furthermore, the method for producing a moisturizing nonwoven fabric according to the present invention can improve properties such as bulkiness and water retention that have been reduced by containing a moisturizing component by performing mechanical processing. It was excellent in workability.

Hereinafter, the moisture retention nonwoven fabric concerning this invention and its manufacturing method are demonstrated in detail based on an Example.
[Examples 1-1 to 1-2, Comparative Example 1]
(Manufacture of non-woven fabric)
Softwood kraft pulp (Howsand 400 manufactured by Canford) was disaggregated with a pulper, and a pulp paper having a basis weight of about 30 g / m ² was produced by a circular net type paper machine. Rayon fiber (1.1 dtex 38 mm) was defibrated with two card machines to produce a pair of fiber webs having a basis weight of about 10 g / m ² . The above pulp paper was sandwiched between a pair of fiber webs and supplied to a conveyor belt. The entanglement integration process was performed with a water jet processing device disposed in the travel path of the conveyor belt, to obtain a spunlace nonwoven fabric containing pulp having a basis weight of 52.4 g / m ² . In the water jet treatment, nozzles having a pore diameter of 80 μm and a pitch of 1 mm were used, and treatment was performed at a water pressure of 4.5 MPa.

(Moisturizing process)
The nonwoven fabric thus obtained was subjected to moisture retention. A moisturizing liquid was applied to the nonwoven fabric by spray coating. It was 74.4 g / m < ² > when the fabric weight of the moisture retention nonwoven fabric was measured after air drying and humidity control. The water-soluble component content of this moisturizing nonwoven fabric was 41.9%, and the amount of increase in equilibrium moisture content was 3.0%.

(Moisturizing ingredient)
The humectant is 60% by weight of glycerin, 10% by weight of sorbitol, 1% by weight of decaglycerin monostearate, 5% by weight of liquid paraffin, 1% by weight of polyoxyethylene (20EO) sorbitan monostearate, 0.1% of sorbitan monostearate. The formulation was 4% by weight and 22.6% by weight of water.

Example 1-1 Dot Embossing (Dry)
The moisturizing nonwoven fabric was pressed with an embossing roll (steel / rubber) and embossed. The emboss shape was a dot shape, the diameter of the emboss was 1 mm, and the number per unit area was 10 / cm ² . Processing was performed using PAPER MACHINE made by Yoshinaga Iron Works Co., Ltd., and the processing conditions were air pressure: 0.5 MPa, processing speed: 2 m / min, processing temperature: 60 ° C.

(Example 1-2) Dot embossing (wet)
20% by weight of water was added to the moisturizing nonwoven fabric by spraying, and then embossed by pressing with an embossing roll (steel / rubber). The emboss shape was a dot shape, the diameter of the emboss was 1 mm, and the number per unit area was 10 / cm ² . Processing was performed using PAPER MACHINE made by Yoshinaga Iron Works Co., Ltd., and the processing conditions were air pressure: 0.5 MPa, processing speed: 2 m / min, processing temperature: 60 ° C.

(Comparative Example 1)
It was set as the nonwoven fabric which performed only the moisture retention process.

  The results of the performance test and the sensory test of Examples 1-1 and 1-2 and Comparative Example 1 are shown in Table 1. The performance test and sensory test of the examples and comparative examples were performed as described below.

<Evaluation>
Examples 1-1 and 1-2 and Comparative Example 1 contain the same amount of moisturizing component, but Examples 1-1 and 1-2 are superior to Comparative Example 1 in the following points. ing.
1) Bending softness / weight per unit area (vertical) is lowered and softness is improved.
2) Both T0 and Tm of KES compression increase and the thickness increases.
3) The water retention rate is rising.
4) In the sensory test, the feeling of softness rises and feels soft. In addition, the moisturizing feeling of the skin is improved, and the transferability of the moisturizing liquid is improved.
5) The wiping property is improved by the unevenness of the surface.

[Examples 2-1 to 2-4, Comparative Example 2]
(Manufacture of non-woven fabric)
Softwood kraft pulp (Howsand 400 manufactured by Canford) was disaggregated with a pulper, and a pulp paper having a basis weight of about 30 g / m ² was produced by a circular net type paper machine. Fibers containing 50% by weight of rayon fibers (1.1 dtex 38 mm) and 50% by weight of PET fibers (1.1 dtex 38 mm) are defibrated with two card machines, and a pair of fiber webs having a basis weight of about 10 g / m ² is obtained. Produced. The above pulp paper was sandwiched between a pair of fiber webs and supplied to a conveyor belt. Entanglement integration processing was performed with a water jet processing device arranged in the travel path of the conveyor belt to obtain a spunlace nonwoven fabric containing pulp having a basis weight of 50.2 g / m ² . In the water jet treatment, nozzles having a pore diameter of 80 μm and a pitch of 1 mm were used, and treatment was performed at a water pressure of 4.5 MPa.

(Moisturizing process)
The nonwoven fabric thus obtained was subjected to moisture retention. A moisturizing liquid was applied to the nonwoven fabric by spray coating. It was 71.6 g / m < ² > when the fabric weight of the moisture retention nonwoven fabric was measured after air drying and humidity control. The water-soluble component content of this moisturizing nonwoven fabric was 42.7%, and the amount of increase in equilibrium moisture content was 4.1%. The same moisturizing liquid as in Example 1 was used as the moisturizing liquid.

Example 2-1 Dot Embossing (Dry)
The moisturizing nonwoven fabric was pressed with an embossing roll (steel / rubber) and embossed. The emboss shape was a dot shape, the diameter of the emboss was 1 mm, and the number per unit area was 10 / cm ² . Processing was performed using PAPER MACHINE made by Yoshinaga Iron Works Co., Ltd., and the processing conditions were air pressure: 0.5 MPa, processing speed: 2 m / min, processing temperature: 60 ° C.

(Example 2-2) Dot embossing (wet)
20% by weight of water was added to the moisturizing nonwoven fabric by spraying, and then embossed by pressing with an embossing roll (steel / rubber). The emboss shape was a dot shape, the diameter of the emboss was 1 mm, and the number per unit area was 10 / cm ² . Processing was performed using PAPER MACHINE made by Yoshinaga Iron Works Co., Ltd., and the processing conditions were air pressure: 0.5 MPa, processing speed: 2 m / min, processing temperature: 60 ° C.

(Example 2-3) Striped embossing (dry)
The moisturizing non-woven fabric was sandwiched between two strip-shaped embossing molds and pressed with a flat press machine to perform striped embossing. The stripe-shaped embossed mold had a pitch of 4 mm and a depth of 2 mm, and was arranged so that a stripe shape could be formed in the lateral direction of the moisturizing nonwoven fabric. The processing conditions were a press pressure: 5 MPa, a press time: 60 seconds, and a processing temperature: 60 ° C.

(Example 2-4) Striped embossing (wet)
After moisture was added to the moisturized nonwoven fabric by spraying at 20% by weight based on the weight of the moisturized nonwoven fabric, the stripe-shaped embossing similar to Example 2-3 was performed. The processing conditions were a press pressure: 5 MPa, a press time: 60 seconds, and a processing temperature: 60 ° C.

(Comparative Example 2)
It was set as the nonwoven fabric which performed only the moisture retention process.

  Table 2 shows the performance test results and sensory test results of Examples 2-1, 2-2, 2-3, 2-4 and Comparative Example 2. The performance test and the sensory test of the examples and comparative examples were performed in the same manner as in Example 1.

<Evaluation>
Examples 2-1 to 2-4 and Comparative Example 2 contain the same amount of moisturizing component, but Examples 2-1 to 2-4 are superior to Comparative Example 2 in the following points. ing.
1) Bending softness / weight per unit area (vertical, horizontal) is lowered and softness is improved.
2) KES compression T0 increases and thickness increases.
3) The water retention rate is rising.
4) In the sensory test, the feeling of softness rises and feels soft. In addition, the moisturizing feeling of the skin is improved, and the transferability of the moisturizing liquid is improved.
5) The wiping property is improved by the unevenness of the surface.

[Example 3, Comparative Example 3]
(Example 3)
(Manufacture of non-woven fabric)
Softwood kraft pulp (Howsand 400 manufactured by Canford) was disaggregated with a pulper, and a pulp paper having a basis weight of about 20 g / m ² was produced by a circular net type paper machine. Rayon fiber (1.7 dtex 38 mm) was defibrated with two card machines to produce a pair of fiber webs with a basis weight of about 10 g / m ² . The pulp paper was sandwiched between a pair of fiber webs and supplied to a 20 mesh conveyor belt. Entanglement integration processing was performed with a water jet processing device arranged in the travel path of the conveyor belt, and a spunlace nonwoven fabric containing pulp having a basis weight of 38.6 g / m ² was obtained. This nonwoven fabric was a 20 mesh mesh nonwoven fabric with through holes corresponding to the mesh of the 20 mesh conveyor belt. The water jet treatment was performed using a nozzle having a pore diameter of 80 μm and a pitch of 0.5 mm, and a water pressure of 4.0 MPa.

(Moisturizing process)
A moisturizing liquid was applied to the mesh nonwoven fabric obtained in this way by a gravure coating method, air-dried and conditioned to obtain a moisturizing nonwoven fabric having mesh irregularities with through holes. It was 48.5 g / m < ² > when the fabric weight of the moisture retention nonwoven fabric was measured. The water-soluble component content of this moisturizing nonwoven fabric was 25.7%, and the amount of increase in equilibrium moisture content was 2.5%. The same moisturizing liquid as in Example 1 was used as the moisturizing liquid.

(Comparative Example 3)
In Example 3, it produced similarly except having set the mesh size of the conveyance belt at the time of a water jet process to 50 mesh. When the mesh size of the conveyor belt was 50 mesh, clear through holes and irregularities on the nonwoven fabric surface were not formed. The basis weight of the nonwoven fabric was 37.0 g / m ² , the basis weight of the moisturizing nonwoven fabric was 45.7 g / m ² , the water-soluble component content was 23.5%, and the increase in equilibrium moisture content was 2.5%.

  Table 3 shows the performance test results and sensory test results of Example 3 and Comparative Example 3. The performance test and the sensory test of the examples and comparative examples were performed in the same manner as in Example 1.

<Evaluation>
Example 3 and Comparative Example 3 contain the same amount of moisturizing component, but Example 3 is superior to Comparative Example 3 in the following points.
1) Bending softness / weight per unit area (vertical, horizontal) is lowered and softness is improved.
2) Both T0 and Tm of KES compression increase and the thickness increases.
3) The water retention rate is rising.
4) In the sensory test, the feeling of softness rises and feels soft.
In addition, the moisturizing feeling of the skin is improved, and the transferability of the moisturizing liquid is improved.
5) The wiping property is improved by the unevenness of the surface.

[Example 4, Comparative Example 4]
Example 4
(Obtaining non-woven fabric)
The test was performed using KP8340 manufactured by Sansho Paper Industry Co., Ltd. KP8340 is a spunlace nonwoven fabric made of pulp and rayon fibers, and has a mesh shape. The mesh size was 8 mesh, the short diameter of the through hole was 512 μm, and the basis weight of the nonwoven fabric was 41.9 g / m ² .

(Moisturizing process)
A moisturizing liquid was applied to the mesh nonwoven fabric thus obtained by a gravure coating method, air-dried and conditioned to obtain a mesh moisture retaining nonwoven fabric with through holes. It was 60.3 g / m < ² > when the fabric weight of the moisture retention nonwoven fabric was measured. The water-soluble component content of this moisturizing nonwoven fabric was 43.9%, and the amount of increase in equilibrium moisture content was 3.1%. The same moisturizing liquid as in Example 1 was used as the moisturizing liquid.

(Comparative Example 4)
It was produced in the same manner as in Example 4 except that KP9340 was used instead of KP8340 used in Example 4.

KP9340 is also a spunlace nonwoven fabric made of pulp and rayon fibers, but the surface of the nonwoven fabric is flat. The basis weight of the nonwoven fabric was 40.4 g / m ² , the basis weight of the moisturizing nonwoven fabric was 57.9 g / m ² , the water-soluble component content was 43.3%, and the increase in equilibrium moisture content was 3.1%.

  The results of the performance test and sensory test of Example 4 and Comparative Example 4 are shown in Table 4. The performance test and the sensory test of the examples and comparative examples were performed in the same manner as in Example 1.

<Evaluation>
Example 4 and Comparative Example 4 contain the same amount of moisturizing component, but Example 4 is superior to Comparative Example 4 in the following points.
1) Softness / weight per unit area is low and soft.
2) Both K0 compression T0 and Tm are high and thick.
3) High water retention rate.
4) In the sensory test, the evaluation of moist feeling and soft feeling is high.
In addition, the moisturizing feeling of the skin is high and the transferability of the moisturizing liquid is high.
5) High wiping property due to surface irregularities.

<Performance test>
Samples were conditioned in a 23 ° C., 50% RH environment according to JIS P8111 (paper, paperboard and pulp—standard conditions for humidity conditioning and testing).
(Weight)
JIS L1913 (General Short Fiber Nonwoven Fabric Test Method) Mass per unit area was taken as the basis weight.

(Water-soluble component content)
The measurement was performed according to the following procedure.

Measure the weight after adjusting the humidity of five samples cut to a size of 100 mm × 100 mm in a standard state (23 ° C., 50%) (the weight is A. That is, A = (weight of non-woven fiber)) + (Equilibrium moisture weight of nonwoven fabric fiber) + (moisturizing component weight) + (equilibrium moisture weight of moisturizing component)). The sample was washed for 10 minutes with stirring in 2 L of distilled water at 60 ° C., and the sample water was sufficiently drained (if there was a drop fiber, filtered using filter paper, and the resulting drop fiber was the same as the nonwoven fabric sample. To the weight B of the nonwoven fabric sample). It is dried for 3 hours using a hot air drier at 105 ° C., and is conditioned again in the standard state (23 ° C., 50%), and the weight is measured (the weight is B. That is, B = (weight of non-woven fiber) ) + (Equilibrium moisture weight of non-woven fiber)). At this time, the water-soluble component content is calculated by the following formula.
Water-soluble component content (%) = (A−B) ÷ B × 100

(Equilibrium moisture content)
Measured by the following procedure with reference to JIS P8127 (paper and paperboard-moisture test method-method using a dryer).

The weight after conditioning the five samples cut to a size of 100 mm × 100 mm in a standard state (23 ° C., 50%) is measured (the weight is A). The sample is put into a weighing bottle (a cylindrical bottle having a barrel diameter of 60 mm and a height of 80 mm is used), the lid is closed, and the weight is measured (the weight is defined as B). Open the lid of the weighing bottle and dry it using a hot air dryer at 105 ° C. for 3 hours, close the lid of the weighing bottle and cool it down to 23 ° C. in a desiccator. And). At this time, the equilibrium moisture content is calculated by the following equation.
Equilibrium moisture content (%) = (BC) ÷ A × 100

(Equilibrium moisture content increase rate)
Using the above method, measure the equilibrium moisture content of the moisturized nonwoven fabric and the equilibrium moisture content of the nonwoven fabric (nonwoven fabric before moisturizing) when water-soluble components are removed from the moisturized nonwoven fabric. did.
Equilibrium moisture content increase rate (%) = (Equilibrium moisture content of moisturizing nonwoven fabric)-(Equilibrium moisture content when water-soluble components are removed from moisturizing nonwoven fabric)

(Difference in unevenness)
About the unevenness | corrugation whose magnitude | size or pitch is 2 mm or less, it measured using the 3D measurement function of 3D real surface view microscope VE-9800 by KEYENCE INC. The magnification was measured at 30 times.

About the thing whose size or pitch is 2 mm or more, it measured using the Kato Tech Co., Ltd. handy compression tester G5. Measurement conditions are SENS: 1, speed range: 0.002 cm / sec, DEF sensitivity: 2, capture interval: 0.1 sec, pressure plate area: 0.5 cm ² (set value of analysis software), compression terminal with 1 mm diameter Was measured, and the difference between the convex portion and the concave portion T0 was defined as the height difference of the concave and convex portions.

(Measurement of the short diameter of through-holes in mesh nonwoven fabric)
It measured using the measurement function of 3D real surface view microscope VE-9800 by KEYENCE Corporation.

(KES compression test)
Kato Tech Co., Ltd. KES FB3 compression tester by the thickness T0 at the load 0.5 gf / cm ² in a standard high-sensitivity conditions, to measure the thickness Tm at the load 10 gf / cm ^2.

(KES pure bending test)
It was measured by Kato Tech Co., Ltd. KES FB2 pure bending tester. The sample width was 200 mm and the measurement was performed under standard high sensitivity conditions.

(Flexibility)
Measured according to JIS L1096 (general textile test method) stiffness and softness E method (handle O meter method). However, the sample size was 100 mm × 100 mm, and the measurement was performed at the center position of the sample. The slit width was 10 mm.

(Water retention rate)
The water retention rate was measured by the following method.

The sample is cut into a size of 100 mm × 100 mm, and the weight after conditioning in a standard state (23 ° C., 50%) is measured (the weight is A). The sample is immersed in distilled water in a vat for 60 seconds, then left on a wire mesh with an inclination angle of 30 ° for 60 seconds, and is quickly placed on a scale and its weight is measured (B is the weight). At this time, the water retention rate is calculated by the following equation.
Water retention rate = (B-A) / A

<Sensory test>
Ten panelists touched each sample by hand and evaluated the following items.
(soft)
Very soft: 4 points, soft: 3 points, slightly soft: 2 points, not soft: 1 point The following notation was made for the total score obtained by summarizing the evaluation points of 10 panelists.
36 to 40 points: ◎, 26 to 35 points: ○, 16 to 25 points: Δ, 10 to 15 points: ×

  The total score was similarly obtained for the following evaluation items, and the same notation was used.

(Smoothness)
Very smooth: 4 points, smooth: 3 points, slightly smooth: 2 points, not smooth: 1 point

(Moist feeling)
Very moist: 4 points, moist: 3 points, slightly moist: 2 points, not moist: 1 point

(Soft feeling)
Very soft: 4 points, soft: 3 points, slightly soft: 2 points, not soft: 1 point

(Clarity of unevenness)
Very clear: 4 points, clear: 3 points, slightly clear: 2 points, not clear: 1 point

(Moisturizing skin)
When the hands were washed with water and then wiped with each sample, the moisture felt on the skin was evaluated.
Strongly moisturizes skin: 4 points, feels moisturized skin: 3 points, feels slightly moisturized skin: 2 points, does not feel moisturized skin: 1 point

(Dirt wiping property)
The experiment was conducted assuming that the dirt around the eyes was wiped so as not to irritate the eyes. I drew a circle with a diameter of 1cm in the center of the palm with a magic and ketchup on the entire palm. Taking care not to touch the ketchup in the circle, the ease of wiping when the ketchup outside the circle was wiped with the sample was evaluated.
Very good wipeability: 4 points, good wipeability: 3 points, slightly good wipeability: 2 points, poor wipeability: 1 point

Claims (10)

  A moisturizing nonwoven fabric containing 1% or more of a water-soluble component relative to the weight of the nonwoven fabric base paper, when the equilibrium moisture content of the moisture retaining nonwoven fabric is compared with the equilibrium moisture content when the water soluble component is removed from the moisture retaining nonwoven fabric A moisture-retaining nonwoven fabric having an equilibrium moisture content increase rate of 0.5% or more, wherein the moisture retention nonwoven fabric has irregularities with a height difference of 100 μm or more on the surface. 2. The moisturizing nonwoven fabric according to claim 1, wherein the surface of the moisturizing nonwoven fabric is dot-like and the number per unit area is 0.6 to 50 / cm ² .   The moisturizing nonwoven fabric according to claim 1 or 2, wherein the surface of the moisturizing nonwoven fabric is striped, and the pitch between the stripes is 1.1 mm or more.   The moisturizing non-woven fabric according to any one of claims 1 to 3, wherein the moisturizing non-woven fabric has mesh-like irregularities and has a mesh size of 2 to 23 mesh.   The moisturizing nonwoven fabric according to any one of claims 1 to 4, wherein the concave and convex portions on the surface of the moisturizing nonwoven fabric are through holes, and the short diameter of the through holes is 100 µm or more.   The method for producing a moisturizing nonwoven fabric according to any one of claims 1 to 4, wherein the unevenness of the surface of the moisturizing nonwoven fabric is formed by embossing.   The method for producing a moisturizing nonwoven fabric according to any one of claims 1 to 4, wherein the surface of the moisturizing nonwoven fabric is formed by embossing in a wet state.   The non-woven fabric is a non-woven fabric produced by a spunlace method, forming irregularities on the surface of the non-woven fabric during hydroentanglement treatment of the non-woven fabric, and then performing a moisturizing process. A method for producing a moisturizing nonwoven fabric.   The method for producing a moisturizing nonwoven fabric according to claim 8, wherein the mesh of the conveyor belt used during the hydroentanglement process is 2 to 23 mesh. The method for producing a moisturizing nonwoven fabric according to claim 8 or 9, wherein a nozzle pitch used during the hydroentanglement treatment is 1.1 mm or more.