JP6121223B2 - Chemical solution impregnated sheet - Google Patents

Description

  The present invention relates to a laminated nonwoven fabric structure comprising a nonwoven fabric layer containing cellulosic fibers and a fine cellulose fiber layer, and a chemical liquid impregnated sheet comprising the nonwoven fabric structure. Specifically, the present invention relates to a liquid impregnated sheet for cosmetic purposes and medical purposes that has particularly high adhesion at the time of wearing and is excellent in liquid chemical retention.

Face masks in which a nonwoven fabric is impregnated with a cosmetic liquid are expanding as anti-aging products for particularly busy modern women in recent years, along with an increase in health and beauty awareness. As a nonwoven fabric conventionally used for a face mask, a cellulose-based short fiber nonwoven fabric represented by cupra long fibers, cotton, and rayon is used as a representative example.
The reason why these cellulose-based nonwoven fabrics are preferably used as cosmetic sheets is because they are more hydrophilic than synthetic fiber-based nonwoven fabrics. It can be mentioned that the time during which the state can be maintained is long and the cosmetic liquid can easily penetrate into the skin.
Cupra filament nonwoven Among cellulosic fiber nonwoven fabric (Asahi Kasei Fibers Corp. Bemliese ^TM) has a small degree of crystallinity in cellulose fibers, cosmetic liquid retention capability is high, and high flexibility when wet Excellent adhesion when worn (stickiness to skin). Moreover, since it is a nonwoven fabric consisting of continuous long fibers and the cross-sectional shape is a round cross section, it is used as a particularly suitable material as a gentle material per skin when worn.

  However, as a beauty sheet, in recent years, there is a demand for a highly adhesive beauty sheet that follows the curved surface and unevenness of the face when worn with respect to the cellulosic fiber nonwoven fabric represented by the above-mentioned cupra long-fiber nonwoven fabric. In particular, there is a demand for a highly adhesive beauty sheet that does not peel off even during movement from the initial wearing stage to removal and during conversations and changes in facial expressions. Therefore, as an improvement from the beauty sheet in order to obtain high adhesion, a face pack using a non-woven fabric layer composed of nanofibers made of a thermoplastic resin having a single fiber diameter of 1 to 500 nm as a sticking surface has been proposed. (See Patent Document 1 below). Since the nanofiber described in Patent Document 1 is composed of a thermoplastic resin, the nanofiber is inferior in flexibility when wet and does not reach a sufficiently satisfactory level from the viewpoint of adhesion.

  In Patent Document 2 below, an ultrafine fiber layer containing 10% by mass or more of ultrafine fibers having a fineness of 0.5 dtex or less is located on one or both surfaces of the hydrophilic fiber layer containing 50% by mass or more of hydrophilic fibers. In addition, a skin covering sheet for impregnating cosmetics having an ultrafine fiber layer as a contact surface with the skin and a face mask impregnated with liquid cosmetics have been proposed. Cellulose fibers such as rayon and pulp are used as the hydrophilic fibers described in Patent Document 2, but in the specification and examples, the ultrafine fibers having a fineness of 0.5 dtex or less are divided from thermoplastic resin. Since the composite fiber is used, it is inferior in flexibility when wet as in Patent Document 1, and has not reached a sufficiently satisfactory level from the viewpoint of adhesion.

Japanese Patent No. 4816312 Japanese Patent No. 3944526

  The problem of the present invention is that the liquid retention performance of the chemical solution and the flexibility when wet are excellent, and the adhesion to the skin when worn is impregnated with the chemical solution for high cosmetic and medical purposes that could not be achieved with conventional nonwoven fabrics. It is providing the sheet | seat and the nonwoven fabric structure used for it.

  As a result of intensive studies, the present inventors have found that a specific fine cellulose fiber layer is laminated in at least one layer or multiple layers on one surface or both surfaces of a nonwoven fabric layer containing cellulosic fibers, and a nonwoven fabric layer containing cellulosic fibers. The present inventors have found that the above-mentioned problems can be solved by a chemical liquid-impregnated sheet obtained by impregnating a nonwoven fabric structure integrated with a chemical liquid into the present invention. That is, the present invention provides the following inventions.

(1) A nonwoven fabric structure in which a fine cellulose fiber nonwoven fabric layer is laminated in at least one layer or multiple layers on one surface or both surfaces of a nonwoven fabric layer containing cellulosic fibers and integrated with the nonwoven fabric layer containing cellulosic fibers. A chemical solution impregnated sheet impregnated with a chemical solution, wherein the fine cellulose fibers forming the fine cellulose fiber nonwoven fabric layer have an average fiber diameter of 0.01 μm or more and 1.5 μm or less, and the fine cellulose fiber nonwoven fabric layer is attached to the skin. A chemical solution impregnated sheet, characterized in that it is a contact surface.
(2) The chemical liquid impregnated sheet as described in (1) above, wherein the total basis weight of the fine cellulose fiber nonwoven fabric layer is 0.5 g / m ² or more and 6 g / m ² or less.
(3) The chemical liquid-impregnated sheet according to item 1 or 2, wherein the nonwoven fabric layer containing cellulosic fibers is a nonwoven fabric layer made of regenerated cellulose fibers and / or natural cellulose fibers.
(4) The liquid impregnated sheet as described in (3) above, wherein the nonwoven fabric layer containing cellulosic fibers is a nonwoven fabric layer composed of regenerated cellulose continuous long fibers.
(5) The above-mentioned 1 characterized in that a substituent having a charge is immobilized on the surface of the fine cellulose fiber nonwoven fabric layer and the surface zeta potential of the contact surface with the skin is in the range of −250 mV to +250 mV. The chemical | medical solution impregnation sheet | seat as described in any one of -4.
(6) The chemical | medical solution impregnation sheet | seat as described in any one of said 1-5 with which 100-2000 weight part chemical | medical solution is impregnated with respect to 100 weight part of nonwoven fabric structures.
(7) A face mask comprising the chemical liquid impregnated sheet according to any one of the above items 1 to 6.

  The present invention is a laminated nonwoven fabric structure of a fine cellulose fiber nonwoven fabric layer and a cellulosic fiber nonwoven fabric layer, and a chemical liquid impregnated sheet such as a face mask made of the nonwoven fabric structure, and has a particularly excellent adhesion at the time of mounting compared to a conventional product. It is possible to design a product that is high and has excellent liquid retention of cosmetics and medical chemicals and excellent chemical penetration into the skin.

Hereinafter, the present invention will be described in detail.
The present invention relates to a nonwoven fabric structure itself described below and a chemical liquid-containing sheet obtained by impregnating the nonwoven fabric structure with a chemical liquid as a cosmetic or a medical chemical liquid. Here, the drug-impregnated sheet means a generic name of a drug-impregnated sheet for cosmetic purposes such as a face mask, and a drug-impregnated sheet for medical purposes such as a wound dressing or a sustained-release patch for drug.
The chemical solution-impregnated sheet of the present invention is prepared by impregnating a chemical solution having a target function in a state where the nonwoven fabric structure defined below in the present invention is impregnated or appropriately by impregnating the chemical solution. The obtained liquid impregnated sheet. In particular, when it is impregnated with a cosmetic drug solution and attached to the face, it can be provided as a face mask. The present invention is obtained by impregnating a non-woven fabric structure including a layer composed of a fine cellulose fiber layer with a chemical solution, the details of which will be described below.

The present invention is a flexible and highly adhesive chemical liquid impregnated sheet that cannot be achieved by a conventional cellulose fiber nonwoven fabric by using cellulosic fibers having a very fine fiber diameter contained in the nonwoven fabric structure. Has been completed. That is, it is a nonwoven fabric structure in which a fine cellulose fiber nonwoven fabric layer is laminated in at least one layer or multiple layers on one surface or both surfaces of a nonwoven fabric layer containing cellulosic fibers and integrated with a nonwoven fabric layer containing cellulosic fibers. And the average fiber diameter of the fine cellulose fiber which forms this fine cellulose fiber nonwoven fabric layer is 0.01 micrometer or more and 1.5 micrometers or less, It is a chemical | medical solution impregnation sheet | seat which uses a fine cellulose fiber nonwoven fabric layer as a contact surface with skin.
The nonwoven fabric structure constituting the chemical liquid impregnated sheet of the present invention needs to include at least one or a plurality of fine cellulose fiber nonwoven fabric layers made of fine cellulose fibers. If the layer made of fine cellulose fibers is not included, the high adhesion required as a chemical solution impregnated sheet, which is the subject of the present invention, cannot be achieved.

The material of the fine cellulose fiber in the present invention is pure cellulose, softwood pulp, hardwood pulp, cotton-derived pulp, hemp-derived pulp, kenaf-derived pulp, bamboo-derived pulp, bagasse-derived pulp, bacterial cellulose, rayon, cupra, lyocell, etc. 60% by weight to 100% by weight of cellulose fibers composed of cellulose derivative fibers such as cellulose acetate, cellulose acetate propionate, cellulose acetate butyrate, carboxymethyl cellulose, carboxyethyl cellulose, nitrocellulose, and methylcellulose It is preferable to contain. If it is less than 60% by weight, fine cellulose fibers may be peeled off from the cellulosic nonwoven fabric.
Other fibers may be mixed as long as the content is 60% by weight or more of cellulose fiber. For example, in order to improve strength, fibers such as polyethylene fiber, polypropylene fiber, nylon fiber, polyketone fiber, and polyester fiber are included. It can be. In addition, it is more preferable that the composition of the fine cellulose fiber which comprises a fine cellulose fiber nonwoven fabric layer is 80 weight% or more from the viewpoint of the adhesiveness in the beauty sheet of this invention, and it is especially preferable that it is 0 weight% or more.

  It is preferable that the fine cellulose fiber which comprises the fine cellulose fiber nonwoven fabric layer contained in the chemical | medical solution impregnation sheet | seat of this invention is a cellulose microfibril. Here, the cellulose microfibril means a cellulose fiber having a fiber diameter of several nm to 200 nm or a convergent body thereof called a microfibril made of natural cellulose or regenerated cellulose. More specifically, cellulose derived from acetic acid bacteria and bacteria, which is called bacterial cellulose, or plant-derived cellulose such as pulp or animal-derived cellulose such as squirt cellulose, called microfibrillated cellulose, is used as a high-pressure homogenizer or super It means independent microfibrils peeled off from the fiber surface or fine fibers in which they are converged, which are obtained by refining with a highly shearing device such as a high-pressure homogenizer or a grinder. In the present invention, it is preferable to use microfibrillated cellulose as a raw material in terms of cost and quality control. Note that the microfibrillated cellulose also includes fine fibers obtained from the cellulose derivative cut yarn by the above-described technique. In addition to this, cut yarns of regenerated cellulose fibers with fine fiber diameters, cut yarns of cellulose derivative fibers with fine fiber diameters, and cut yarns of regenerated cellulose or cellulose derivative ultrafine yarns obtained by electrospinning are also fine cellulose. Can be used as fiber.

  In this invention, the fiber diameter of the fiber which comprises a fine cellulose fiber nonwoven fabric means a weight average fiber diameter, and it is important that this fiber diameter is 0.01 micrometer or more and 1.5 micrometers or less. The thinner the fiber diameter, the higher the adhesion of the chemical solution impregnated sheet, but it is difficult to produce fine cellulose fibers of less than 0.01 μm. Preferably, the fiber diameter of the fine cellulose fiber is 0.02 μm or more and 1.2 μm or less, and more preferably 0.02 μm or more and 0 when considering the production and adhesion feeling of the stable fine cellulose fiber on an industrial scale. .8 μm or less.

  The fine cellulose fiber which comprises the fine cellulose fiber nonwoven fabric layer contained in the chemical | medical solution impregnation sheet | seat of this invention may be chemically modified. For example, some or most of the hydroxyl groups present on the surface of fine cellulose fibers (cellulose microfibrils) are esterified including acetate ester, nitrate ester, sulfate ester, phosphate ester, alkyl typified by methyl ether, etc. Ether, carboxy ether typified by carboxymethyl ether, etherified one containing cyanoethyl ether, or a hydroxyl group at the 6-position oxidized by a TEMPO oxidation catalyst to form a carboxyl group (including acid type and salt type) Can be included.

The total basis weight of the fine cellulose fiber layer constituting the fine cellulose fiber nonwoven fabric layer contained in the chemical liquid impregnated sheet of the present invention is preferably 0.5 g / m ² or more and 10 g / m ² or less, more preferably 0.5 g. / M ² or more and 6 g / m ² or less, particularly preferably 0.7 g / m ² or more and 5 g / m ² or less. This is because the fine cellulose fiber layer has higher density and rigidity than the non-woven fabric layer containing cellulosic fibers, and therefore, when the total basis weight of the fine cellulose fiber layer exceeds 6 g / m ² , This is because the rigidity increases and the sheet impregnated with the chemical solution becomes poor in flexibility, so that it is difficult to follow the curved surface of the skin when it is applied on the skin. Although the basis weight can be lowered as much as possible in design, the basis weight is preferably 0.5 g / m ² or more from the viewpoint of expression of performance and quality control of manufacturing technology. If the basis weight is smaller than this, the high adhesion to the skin expressed by the chemical liquid impregnated sheet of the present invention is not clear, and at the same time, it is difficult to uniformly laminate the nonwoven fabric containing cellulosic fibers.

Furthermore, in the present invention, a substituent having a charge is immobilized on the surface of the fine cellulose layer, and the surface zeta potential of the contact surface with the skin is in the range of −250 mV to +250 mV, more preferably −150 mV to +150 mV. If controlled within the following range, it is possible to appropriately control the state of contact with the skin and the permeability of the drug solution into the skin, and thus can be said to be one of the preferred embodiments of the present invention.
For example, a healthy skin state is said to exhibit a zeta potential of about −40 mV, whereas a compound having a cationic substituent, such as a compound having a quaternary ammonium group, is subjected to physical adsorption or surface reaction. When introduced to the surface of the fine cellulose fiber in the fine cellulose fiber layer of the present invention by the chemical interaction, the attractive interaction is increased by the electrostatic interaction between the healthy skin and the surface of the chemical impregnation sheet of the present invention. This is preferable because the adhesion of the sheet to the skin is increased.

  In addition, when a suitable amount of a compound having a strong anionic substituent, for example, a p-benzenesulfonic acid group having a sulfone group or an alkylsulfonic acid group, is introduced by a surface reaction, the surface zeta potential is controlled to a large negative value. However, if a large surface potential difference is provided between the surface in contact with the skin and the skin, the same effect as when an electric field is applied to the surface of the skin appears. According to a patent document (Japanese Patent Laid-Open No. 2002-291909), when a weak electric field of about 500 mV is applied to the surface of the skin, a remarkable effect can be expected in the recovery of the barrier function of the skin. When a large negative surface potential is applied to the fine cellulose fiber layer as a surface, for example, as an absolute value exceeding -100 mV, the same effect can be expressed by a potential difference from the skin surface.

  Further, when the chemical liquid impregnated in the chemical liquid-impregnated sheet contains an ionic compound having a charge, the compound is obtained by providing a potential difference (electric field) between the chemical liquid-impregnated sheet and the skin. The compound itself or a compound that interacts with the compound can be fed into the skin, that is, a pumping action by an electric field gradient can be imparted, and the chemical penetration into the skin can be enhanced, which is sometimes effective. That is, by controlling the zeta potential within a predetermined range, in addition to the function of the chemical liquid-impregnated sheet having high adhesion to the skin defined in the present invention, it is not found in the conventional chemical liquid-impregnated sheet of the chemical liquid to the skin. A plurality of effects can be imparted. The effect may be appropriately selected according to the needs required for the chemical liquid impregnated sheet, and a zeta potential suitable for the required effect may be set.

  As methods for introducing a substituent having a charge, two methods, physical adsorption and surface reaction, can be mentioned. In the case of the physical adsorption method, utilizing the fact that the surface of the fine cellulose fiber forming the fine cellulose fiber layer in the present invention usually has a negative zeta potential of about −30 mV, a cationic substituent is added to the surface. The compound is physically adsorbed and immobilized. In addition to the interaction between charges, the motive force of adsorption also acts as an attractive interaction due to hydrogen bonding. Therefore, if a strong cationic compound is successfully adsorbed, a positive charge of up to about +100 mV can be introduced by this method. Is possible. Further, a negative surface potential can be imparted by physically adsorbing a negatively charged compound in the same manner on the positively charged surface. By making full use of such alternate adsorption technology (alternate adsorption method), it is possible to control the surface of the fine cellulose fiber in a zeta potential range of −150 mV to +150 mV. In the production of the chemical solution-impregnated sheet of the present invention, first, a compound having a charge is fixed to the surface of fine cellulose fibers in an aqueous dispersion for papermaking by alternating adsorption method or the like, and the zeta potential is controlled, and then a laminated sheet by papermaking method. Even if it makes it, after manufacturing a lamination sheet previously, you may control zeta potential with an alternate adsorption method etc. with respect to this sheet | seat.

  In such a physical adsorption method, a cationic or anionic compound is adsorbed and immobilized on the surface of fine cellulose fibers. Specifically, amine base, quaternary ammonium base, carboxylate base, sulfonate group, phosphoric acid An ionic compound having a base or nitrate group in the molecule, more specifically, anionic surface activity such as alkyl sulfate ester salt, polyoxyethylene alkyl sulfate ester salt, alkylbenzene sulfonate, α-olefin sulfonate And cationic surfactants such as agents, alkyltrimethylammonium chloride, dialkyldimethylammonium chloride, benzalkonium chloride, and ionic water-soluble polymers such as cationized polyvinyl alcohol and anionized polyvinyl alcohol. Is limited to these Not to.

Next, a surface reaction method as a second method for introducing a charged substituent will be described. Since the fine cellulose fiber contained in the chemical liquid impregnated sheet of the present invention contains a large number of hydroxyl groups on the surface, a compound having a charge is introduced by a chemical reaction utilizing the reactivity of the hydroxyl groups. As the chemical reaction at this time, it is possible to use all chemical reactions represented by reactions to hydroxyl groups, that is, esterification, etherification, silicateization, urethanization, carboxylation by TEMPO oxidation, and the like. In this method, since the structure of the compound can be designed freely, for example, surface reaction with a compound (for example, para-benzenesulfonate isocyanate) designed with a strong ionic substituent located slightly away from the reaction site. Thus, it is possible to introduce a large surface potential as an absolute value, and the surface zeta potential of the contact surface with the skin of the chemical liquid impregnated sheet of the present invention can be controlled in the range of −250 mV to +250 mV. Also in this method, as in the case of the physical adsorption method, in the production of the chemical liquid-impregnated sheet of the present invention, a compound having a charge is introduced into the surface of fine cellulose fibers in the aqueous dispersion for papermaking by surface reaction in advance. Even if the laminated sheet is formed by the papermaking method after controlling the potential, the zeta potential may be controlled by surface reaction with respect to the sheet after the laminated sheet is first manufactured.
By such a surface reaction method, an amine base or a quaternary ammonium base can be introduced as a cationic group, and a carboxylate base, a sulfonate group, a phosphate base, or a nitrate base can be introduced as an anion group.

Cellulosic fibers constituting the nonwoven fabric containing the cellulose fibers used in the chemical-impregnated sheet of the present invention include natural fibers typified by cotton, pulp and hemp, and regeneration typified by viscose rayon, polynosic rayon, and cupra. Cellulose fibers, purified cellulose by solvent spinning, and the like, and two or more of these fibers may be used. The fiber diameters of these natural cellulose fibers, regenerated cellulose fibers, and purified cellulose fibers are not particularly limited, and the fiber length is not limited at all, and short fibers (fiber length 2 mm to 100 mm) and long fibers are used. be able to.
The mixing ratio of these cellulose fibers constituting the nonwoven fabric containing cellulosic fibers is preferably 60 wt% or more, more preferably 80 wt% or more. The fiber type, fiber diameter, and fiber length used in addition to the cellulose fiber are not limited at all, and fibers such as polyester, nylon, and acrylic are given as representative examples.
Nonwoven fabrics containing cellulosic fibers include card webs in which short fibers are arranged in one direction, airlaid nonwoven fabrics and wet papermaking webs in which short fibers are randomly collected, and these fibers by needle punching or hydroentanglement. Non-woven fabrics that are three-dimensionally entangled can be mentioned.
The basis weight of the nonwoven fabric containing cellulosic fibers, particularly non but preferably in a range of 10g / m ² ~180g / m ² restricted, and even more preferably from ^{10g / m 2 ~150g / m 2} .

  As the nonwoven fabric containing a more preferable cellulosic fiber used in the chemical liquid-impregnated sheet of the present invention, the liquid retention of cosmetic liquids and medical chemical liquids, the flexibility when wet, and finally the adhesion at the time of wearing are improved. From the point of improvement, a nonwoven fabric composed of 100% cellulose fiber can be mentioned. In addition, when a fine cellulose fiber nonwoven fabric layer and a nonwoven fabric layer containing cellulosic fibers are combined, the cellulose fiber 100 wt% also from the physical properties such as the peelability between the laminated composite sheets and the prevention of falling off of the fine cellulose fibers in contact with the skin surface. The nonwoven fabric which consists of is more preferable.

A more preferable nonwoven fabric layer containing cellulosic fibers is a nonwoven fabric layer composed of regenerated cellulose fibers and / or natural cellulose fibers, and a regenerated cellulose continuous long fiber nonwoven fabric is particularly preferable. As a specific example of regenerated cellulose continuous fiber, a cupra ammonium method rayon stock solution is continuously spun onto the net by the falling tension spinning method, and the fibers are entangled by self-adhesion of the fiber itself or hydroentanglement as necessary to make a nonwoven fabric. Regenerated cellulose continuous long fibers (registered trademark: Benrise ^™ manufactured by Asahi Kasei Fibers Co., Ltd.). Regenerated cellulose continuous fiber (Benlyse) is less crystallized than other cellulosic fibers such as cotton and rayon, so it has high liquid retention when wet and excellent flexibility when wet. When laminated with a fine cellulose fiber layer, an extremely high feeling of adhesion and a strong pulling feeling can be obtained as compared with the case of using a nonwoven fabric made of other cellulosic fibers.

Benlyse is self-adhesive with many continuous long fibers coagulating in a spinning bath, so even if the nonwoven fabric has a small basis weight, it has a high sheet strength when wet. It has a feature that it is easy to reduce the weight and thickness of the body. A typical basis weight of a commercially available Benrize is 5 g / m ^{2 to} 150 g / m ² , and a high basis weight is also applicable depending on the required characteristics of the chemical liquid impregnated sheet. Further, Benlyse has a characteristic that it easily stretches in the weft direction when wet, as one of the features that come from its manufacturing method. In addition to this property, the adhesion with the fine cellulose fiber is greatly improved. For example, when wearing a face mask, both cheeks are forcibly pulled and the cheeks are lifted. It is possible to have a feature that is excellent in performance to maintain (lifting performance).
In this case, as the tensile property when the Benize used is wet, the elongation under a stress of 100 g / cm is 25-50 in a 20 cm × 20 cm sample using a KES-FB1 machine manufactured by Kato Tech Co., Ltd. If a base material having a weigh elongation of about% and a basis weight of 60-150 g / m ² is selected, a laminated composite sheet excellent in lift-up performance can be obtained.

Further, since Benlyse has excellent flexibility properties when wet as described above, it has suitability as a base material for a face mask, but the basis weight of Benlyse is 30-60 g / m ² . In a relatively low weight area, the handling property when being impregnated with a chemical (especially a high-viscosity chemical) or being applied to the face becomes poor. By laminating and compounding with fine cellulose fibers, the handleability during chemical impregnation is greatly improved even in a low basis weight region.
The fineness of the regenerated cellulose continuous long fiber is applicable in the range of 0.1 dtex to 3 dtex, but considering that it is used as a composite with the fine cellulose fiber, it can maintain the entanglement strength with the fine cellulose fiber and A range of 0.1 to 2.0 dtex is preferable from the viewpoint of adhesion at the time of mounting.

In the chemical solution impregnated sheet of the present invention, those having a total weight of the nonwoven fabric structure of 10 g / m ² or more and 200 g / m ² or less are preferably used. When it is less than 10 g / m ² , the mechanical strength for use as a chemical liquid impregnated sheet cannot be obtained, and the handleability when worn on the skin surface is deteriorated. A non-woven fabric structure having a basis weight exceeding 200 g / m ² is inferior in flexibility when wet, so that a high feeling of adhesion cannot be obtained. Preferably at 10 g / m ² or more 150 g / m ² or less, more preferably 15 g / m ² or more 120 g / m ² or less.
In the chemical solution impregnated sheet of the present invention, considering the fact that it is a non-woven structure having a two-layer structure comprising a fine cellulose fiber non-woven fabric layer and a non-woven fabric layer containing cellulosic fibers, the basis weight of the fine cellulose fiber non-woven fabric layer is 0 for economic reasons. .5g / m ² or more 10 g / m ² or less and a basis weight of the nonwoven fabric layer 10 g / m ² or more 180 g / m ² or less of designs, including cellulosic fibers, more preferably, the basis weight of the fine cellulose fiber nonwoven fabric layer 1.0g / M ² or more and 6 g / m ² or less and the basis weight of the nonwoven fabric layer containing cellulosic fibers is designed to be 15 g / m ² or more and 120 g / m ² or less, achieving high adhesion performance and good handleability required as a chemical-impregnated sheet It is preferable because it is possible.

The film thickness of the nonwoven fabric structure used for the chemical liquid impregnated sheet of the present invention is preferably 20 μm or more and 800 μm or less. When the film thickness is less than 20 μm, the mechanical strength for use as a chemical solution impregnated sheet is small, and the handleability is poor. If it exceeds 800 μm, the adhesion performance and the touch will be poor, and the wrapping will be inferior. In order to use suitably, More preferably, they are 30 micrometers or more and 600 micrometers or less, Most preferably, they are 50 micrometers or more and 500 micrometers or less.
The chemical liquid impregnated sheet of the present invention is impregnated with 100 to 2000 parts by weight of chemical liquid with respect to 100 parts by weight of the nonwoven fabric structure, although it varies depending on the purpose.

Hereinafter, an example of a method for producing fine cellulose fibers (preferably cellulose microfibrils) used in the chemical liquid-impregnated sheet of the present invention will be described.
As raw materials when using microfibrillated cellulose, so-called wood pulp and non-wood pulp such as softwood pulp and hardwood pulp can be used. Examples of non-wood pulp include cotton-derived pulp including cotton linter pulp, hemp-derived pulp, bagasse-derived pulp, kenaf-derived pulp, bamboo-derived pulp, and straw-derived pulp. Cotton-derived pulp, hemp-derived pulp, bagasse-derived pulp, kenaf-derived pulp, bamboo-derived pulp, straw-derived pulp are cotton lint, cotton linter, hemp-based abaca (for example, many from Ecuador or the Philippines), It means a refined pulp obtained through a refining process such as delignification by a digestion process or a bleaching process for raw materials such as zaisal, bagasse, kenaf, bamboo, and straw. In addition, purified seaweed-derived cellulose and sea squirt cellulose can also be used as raw materials for microfibrillated cellulose. Furthermore, a cut yarn of regenerated cellulose fiber or a cut yarn of cellulose derivative fiber can be used as the raw material, and a cut yarn of regenerated cellulose or cellulose derivative obtained by electrospinning is also a raw material of microfibrillated cellulose or It can be used as fine cellulose fiber itself.

Next, a method for microfibrillation of cellulose fibers will be described. The cellulose fibers are preferably microfibrillated through a pretreatment step, a beating treatment step, and a refinement step.
In the pretreatment step, it is effective to make the raw material pulp easy to be refined by autoclave treatment under water impregnation at a temperature of 100 to 150 ° C., enzyme treatment, or a combination thereof. These pretreatments not only reduce the load of the micronization process, but also discharge impurity components such as lignin and hemicellulose present on the surface and gaps of the microfibrils that make up the cellulose fibers to the aqueous phase, resulting in a finer process. There is also an effect of increasing the α-cellulose purity of the formed fiber.

In the beating treatment step, the raw material pulp is 0.5 wt% or more and 4 wt% or less, preferably 0.8 wt% or more and 3 wt% or less, more preferably 1.0 wt% or more and 2.5 wt% or less. Disperse in water to a partial concentration and highly promote fibrillation with a beating device such as a beater or disc refiner (double disc refiner). When using a disc refiner, if the clearance between the discs is set as narrow as possible (for example, 0.1 mm or less) and processing is performed, extremely advanced beating (fibrillation) proceeds, so miniaturization with a high-pressure homogenizer etc. The processing conditions can be relaxed and may be effective.
A preferable degree of beating processing is determined as follows.

  In our study, as the beating process was performed, the CSF value (indicating the degree of beating of cellulose and evaluated by the Canadian standard freeness test method for pulp as defined in JIS P 8121) decreased with time. After becoming close to zero, the tendency to increase again after further beating treatment was confirmed, and as a highly fibrillated fiber that is a raw material of microfibrillated cellulose used in preparing an aqueous dispersion, It turned out that it is preferable to continue the beating process and beat the CSF value until the CSF value is increased after the CSF value once approaches zero. In the present invention, the CSF value in the process of decreasing the CSF value from unbeaten is expressed as *** ↓, and the CSF value in a tendency to increase after becoming zero is expressed as *** ↑. In the beating process, the CSF value is preferably at least zero, more preferably CSF 30 ↑ or higher (higher beating degree). In the aqueous dispersion (hereinafter also referred to as “slurry”) prepared to such a beating degree, fibrillation proceeds to a high degree, and at the same time, it is possible to provide a raw material that does not contain coarse cellulose fibers exceeding the maximum fiber diameter of 2500 nm. The fine cellulose fiber layer obtained from the slurry tends to have improved tensile strength due to an increase in the adhesion point between cellulose microfibrils. Moreover, highly refined slurries with a CSF value of at least zero or a *** ↑ value that increases thereafter increase in homogeneity and can reduce clogging due to subsequent refinement by a high-pressure homogenizer or the like. There are advantages.

For the production of microfibrillated cellulose, a high-pressure homogenizer, an ultra-high pressure homogenizer, a grinder or the like can be used. In this case, the solid content concentration in the aqueous dispersion is 0.5% by weight or more and 4% by weight or less, preferably 0.8% by weight or more and 3% by weight or less, more preferably 1.0%, in accordance with the beating treatment described above. If the solid content concentration is in the range of not less than 2.5% by weight, clogging does not occur and an efficient miniaturization process can be achieved.
Examples of high-pressure homogenizers used include NS type high-pressure homogenizers from Niro Soabi (Italy), SMT's Lanier type (R model) pressure-type homogenizers, and Sanwa Kikai Co., Ltd. high-pressure homogenizers. Any device other than these devices may be used as long as the device performs miniaturization by a mechanism substantially similar to those of these devices. Ultra-high pressure homogenizers mean high-pressure collision type miniaturizers such as Mizuho Kogyo Co., Ltd. microfluidizer, Yoshida Kikai Kogyo Co., Ltd. Nanomizer, and Suginoma Machine Co., Ltd. Any device other than these devices may be used as long as the device performs miniaturization with a substantially similar mechanism. Examples of the grinder-type miniaturization device include the pure fine mill of Kurita Machinery Co., Ltd. and the stone mill type milling die represented by Masuyuki Sangyo Co., Ltd. Any device other than these may be used as long as the device performs miniaturization by this mechanism.
The fiber diameter of the microfibrillated cellulose is determined by the conditions of the refinement using a high-pressure homogenizer (selection of equipment and operating pressure and the number of passes) or the pretreatment conditions before the refinement (for example, autoclave treatment, enzyme treatment, beating Control).

Next, it describes about the manufacturing method of the nonwoven fabric layer structure containing the fine cellulose fiber nonwoven fabric layer and cellulose fiber which are used by this invention. As a manufacturing method, it can be manufactured by a papermaking method.
The method of forming a fine cellulose fiber nonwoven fabric layer by a papermaking method using an aqueous dispersion of fine cellulose fibers described above is laminated on a nonwoven fabric containing cellulosic fibers from a predetermined aqueous dispersion of fine cellulose fibers by a papermaking method. It is a simple thing which dries the nonwoven fabric structure which is a body.

  That is, (1) a preparation step of preparing an aqueous dispersion containing 0.05% to 0.5% by weight of fine cellulose fibers and 85% to 99.5% by weight of water, and (2) an aqueous dispersion. A step of paper-making a concentrated composition in which the concentration of fine cellulose fibers is increased from that of the aqueous dispersion by dehydrating a part of the constituent water with a paper machine on a nonwoven fabric containing the cellulose-based fibers; (3) A method for producing a nonwoven fabric structure comprising three steps: a drying step in which water is evaporated and removed by heating a nonwoven fabric structure in which fine cellulose fibers and a nonwoven fabric containing cellulose fibers are laminated and integrated. is there. By adopting the papermaking method in (2), the chemical liquid impregnated sheet of the present invention can be suitably produced.

Details of the three steps described above will be described.
First, the aqueous dispersion used in the preparation step (1) is an aqueous dispersion containing 0.01% to 0.5% by weight of fine cellulose fibers and 85% to 99.99% by weight of water. Is preferred.
The concentration of fine cellulose fibers in the aqueous dispersion for papermaking is 0.01 wt% or more and 0.5 wt% or less, more preferably 0.03% by weight or more and 0.35 wt% or less, most preferably 0.05. A stable papermaking can be carried out when the content is not less than 0.3% by weight. When the concentration of the fine cellulose fibers in the aqueous dispersion is lower than 0.01% by weight, the drainage time becomes very long, the productivity is remarkably lowered, the yield of the fine cellulose fibers is deteriorated and the film quality uniformity is remarkably increased. Since it gets worse, it is not preferable. On the other hand, if the concentration of the fine cellulose fiber is higher than 0.5% by weight, the viscosity of the dispersion liquid is excessively increased, and it becomes difficult to form a uniform film, which is also not preferable.
The solvent of the fine cellulose fiber dispersion for papermaking may be water alone, but in some cases, for example, various compounds may be added for the purpose of controlling various physical properties.

  When designing the porosity of the fine cellulose fiber nonwoven fabric layer in the nonwoven fabric structure, an organic solvent that dissolves in water or a hydrophobic organic solvent that does not dissolve is added to water, which is a solvent. Or it is good also as an emulsion of an organic solvent. Examples of organic solvents that dissolve in water include cellosolves such as methanol, ethanol, iso-propanol, and methyl cellosolve, and hydrophobic organic solvents that do not dissolve include hydrocarbons such as n-decane and toluene, 1-hexanol. Long-chain alcohols such as 1-heptanol and the like, but are not limited thereto. Assuming that the organic solvent to be used is removed in the drying step described later, the boiling point is preferably 160 ° C. or lower. Moreover, the chemical-impregnated sheet of the present invention can be obtained at a relatively low cost when the composition of the organic solvent used in the entire solvent is 10% by weight or less, more preferably 3% by weight or less, for economic reasons.

  In this papermaking method, a water-soluble polymer effective as a reinforcing binder for the fine cellulose fiber nonwoven fabric layer may be contained, and the water-soluble polymer effectively remains on the cellulose surface, so that it is effective as a reinforcing binder. Works. It is preferable that the specific water-soluble compound described above is dissolved in the aqueous phase in the aqueous dispersion in the papermaking method. The concentration of the specific water-soluble polymer is 0.003% to 0.3% by weight, more preferably 0.005% to 0.08% by weight, and still more preferably 0.006% by weight. The amount is 0.07% by weight or less, and this range is preferable because the fine cellulose fiber used in the present invention can be easily obtained and the state of the aqueous dispersion is often stabilized. If the concentration is less than 0.003% by weight, the effect of adding the specific water-soluble compound is hardly exhibited, and it is not preferable. If the concentration exceeds 0.3% by weight, the amount of addition such as foaming increases. Since a negative effect tends to appear, it is not preferable. In addition, for the purpose of stabilizing the aqueous dispersion, a surfactant may be contained in the aqueous dispersion in addition to the specific water-soluble compound, and the total amount with the specific water-soluble polymer may be included in the concentration range. I do not care.

  As the surfactant in this case, an anionic surfactant such as alkyl sulfate ester salt, polyoxyethylene alkyl sulfate ester salt, alkylbenzene sulfonate, α-olefin sulfonate, alkyltrimethylammonium chloride, dialkyldimethylammonium chloride, Examples include cationic surfactants such as benzalkonium chloride, amphoteric surfactants such as alkyldimethylaminoacetic acid betaines and alkylamidodimethylaminoacetic acid betaines, and nonionic surfactants such as alkylpolyoxyethylene ethers and fatty acid glycerol esters. However, it is not limited to these.

  The total amount of components other than water in the aqueous dispersion is 0.01% by weight or more and 15% or less, preferably 0.02% by weight or more and 10% by weight or less, more preferably 0.03% by weight or more and 8% or less. The composition is preferably dispersed or dissolved in water. If the composition of water in the aqueous dispersion is lower than 85% by weight, the viscosity increases in many cases, and it becomes difficult to uniformly disperse the slurry in the dispersion, and a fine cellulose fiber nonwoven fabric layer having a uniform structure is obtained. Since it becomes difficult, it is not preferable. In addition, when the composition of water in the aqueous dispersion exceeds 99.99% by weight, the content of fine cellulose fibers is reduced as a blended composition, and the drainage during papermaking is significantly deteriorated, which adversely affects productivity. Absent.

The aqueous dispersion is prepared by mixing all additives into water and preparing an aqueous slurry dispersion by an appropriate dispersion method, or mixing an aqueous solution containing the additive in advance with separately prepared cellulose microfibrils. In this case, it is preferable to control and adjust with a disperser or a high-pressure homogenizer that rotates blades having a cutting function such as a blender at high speed so that the average dispersion diameter is 1 μm or more and 300 μm or less. . Here, (a later, R _v) dispersion average diameter of the fine cellulose fibers in papermaking dispersion, water permeability, 1 [mu] m or more from the viewpoint of efficiency of the paper making point of uniformity of fine cellulose fiber nonwoven fabric layer To 300 μm or less is preferable. The dispersion average diameter (R _v ) as used herein refers to a dispersion for papermaking using a laser scattering particle size distribution measuring device (manufactured by Horiba, Ltd., laser diffraction / scattering particle size distribution measuring device LA-920, the lower limit detection value is 0.02 μm), which means a volume average arithmetic average diameter obtained by measurement at room temperature. In this measurement, the volume distribution is based on Mie's scattering theory (M. Kerker, “The Scattering of Light”, USA, Academic Press, New York, NY, 1969, Cap. 5.). The arithmetic average diameter is used, and the relative refractive index of the cellulose used in this case with respect to the refractive index of water is 1.20.
R _v of papermaking dispersion, preferably 3μm or more 200μm or less, more preferably to be in the 100μm below the range of 5 [mu] m, it is possible to provide good yield nonwoven fabric of the present invention having more excellent uniformity.

Next, the second step (2) of the papermaking method is a papermaking step of filtering the fine cellulose fibers and concentrating the aqueous dispersion by dehydrating the composite structure prepared in the first step with a paper machine. It is. The paper making process is basically a filter or filter cloth (also called a wire in the technical field of papermaking) in which water is dehydrated from a dispersion containing water and fine cellulose fibers remain on the nonwoven fabric containing cellulosic fibers. Any device may be used as long as the operation is used.
As the paper machine, a sheet-like fine cellulose fiber nonwoven fabric layer with few defects can be suitably obtained by using an apparatus such as an inclined wire type paper machine, a long net type paper machine, or a circular net type paper machine. Whether the paper machine is a continuous type or a batch type, it may be properly used according to the purpose.

Dewatering is carried out by the papermaking process using the aqueous dispersion (for papermaking) obtained in the preparation process. Papermaking is performed by running a nonwoven fabric made of cellulosic fibers on a wire or filter cloth and dispersed in the aqueous dispersion. Since this is a step of filtering soft agglomerates such as fine cellulose, the size of the wire or filter cloth is important. In the present invention, the aqueous dispersion for papermaking prepared under the above-mentioned conditions is essentially a water-insoluble component yield ratio including fine cellulose fibers contained in the dispersion, preferably 70% by weight or more. Any wire or filter cloth can be used as long as it can produce paper at 95% by weight or more, more preferably 99% by weight or more.
Examples of filters or filter cloths that can be used even for extremely fine cellulose fibers include TETEXMONODLW07-8435-SK010 (PET) manufactured by SEFAR (Switzerland), NT20 (PET / nylon blend) manufactured by Shikishima Canvas. However, it is not limited to these. In the concentration step (2), the chemical solution-impregnated sheet of the present invention can be suitably provided even if an apparatus described in the document: Japanese Patent Application Laid-Open No. 2011-042903 is used.

In dehydration by the papermaking process, high solid differentiation proceeds, and wet paper (a solution containing a solvent in the dispersion or a concentrated composition in which the concentration of fine cellulose fibers is increased from the aqueous dispersion prepared in step (1)). When an emulsion is used, a concentrated paper (wet paper) is obtained. The solid content ratio of the wet paper is controlled by the degree of dehydration by the suction pressure (wet suction or dry suction) of the papermaking or pressing process, preferably the solid content concentration is 6 wt% or more and 50 wt% or less, more preferably solid content The concentration is adjusted in the range of 8% by weight to 40% by weight. If the solid content of the wet paper is lower than 6% by weight, there is no self-supporting property as the wet paper and problems in the process are likely to occur. Further, it is difficult to dehydrate the wet paper to a concentration exceeding 50% by weight because the nonwoven fabric structure constituting the present invention has high liquid retention, and the solid content is less than 6% by weight. Controlling the solid content ratio is not preferable because the drying cost increases.
Alternatively, paper making may be performed on the filter cloth, and water in the obtained wet paper may be substituted with an organic solvent in a substitution step with an organic solvent and dried. This method is effective when designing a high porosity to improve moisture permeability, but the resistance to air permeability is reduced compared to the case where it is not replaced. decide.

In addition, the support body which is a nonwoven fabric layer containing a cellulosic fiber is placed on a paper machine set with a wire or a filter cloth, and a part of water constituting the aqueous dispersion is dehydrated on the support body ( A multilayered sheet composed of a multilayer structure of at least two or more layers is manufactured by laminating and integrating a wet paper of a fine cellulose fiber nonwoven fabric composed of microfibrillated cellulose on the support. be able to. In order to produce a multilayer sheet having three or more layers, a support having a multilayer structure having two or more layers may be used. Moreover, it is good also as a multilayer sheet | seat of three or more layers by performing the multistage papermaking of the fine cellulose fiber nonwoven fabric of this invention of two or more layers on a support body.
Here, as a papermaking method of the aqueous dispersion, the aqueous dispersion is usually made on a wire or a filter cloth at room temperature. In some cases, it is also effective to set the temperature of the aqueous dispersion higher than room temperature in order to increase the productivity by lowering the viscosity of water and reducing the resistance to drainage. In this case, from the viewpoint of process control, the temperature of the dispersion is preferably in the range of 35 ° C. or more and 60 ° C. or less.

  The wet paper obtained in the paper making process becomes a fine cellulose fiber nonwoven fabric layer by evaporating a part of water in the drying process by heating. In the drying process, if a constant-length dryer that can dry water is used with a constant width like a drum dryer, a fine cellulose fiber nonwoven fabric layer with high air resistance can be stably formed. Since it can obtain, it is preferable. The drying temperature may be appropriately selected according to the conditions, but is preferably 45 ° C. or higher and 180 ° C. or lower, more preferably 60 ° C. or higher and 150 ° C. or lower. A nonwoven fabric structure including a nonwoven fabric layer can be produced. When the drying temperature is less than 45 ° C., the evaporation rate of water is slow in many cases, and it is not preferable because productivity cannot be ensured. When the drying temperature is higher than 180 ° C., a consumable agent such as felt normally constituting a drying part. This is not preferable because it significantly impairs the durability. For example, when forming a wet paper having a multilayer structure with papermaking from the aqueous dispersion which is the emulsion described above, the composition is prepared by drying at a low temperature of 100 ° C. or lower and dried at a temperature of 100 ° C. or higher in the next stage. It may be effective to carry out the multi-stage drying to obtain a highly uniform fine cellulose fiber nonwoven fabric layer.

Hereinafter, the present invention will be described in more detail with reference to examples. The main measured values of physical properties were measured by the following methods.
(1) Average fiber diameter of fine cellulose fibers With respect to the surface of the non-woven filter medium made of fine cellulose fibers, observation is performed at 3 locations at random at a magnification equivalent to 10,000 times with a scanning electron microscope (SEM). With respect to the obtained SEM image, a line is drawn in the horizontal direction and the vertical direction with respect to the screen, and the fiber diameter of the fiber intersecting the line is measured from the enlarged image, and the number of intersecting fibers and the fiber diameter of each fiber are counted. In this way, the weight average fiber diameter _Rw is calculated by the following formula using the measurement results of two vertical and horizontal series per image.
R _w = Σ (R _i ) ³ / Σ (R _i ) ²
Here, R _i means the diameter of the fiber that is observed individually, and Σ means the sum total of the number i of the function. Further, R _w is calculated in the same manner for the other two extracted SEM images, and the results for a total of three images are averaged to obtain the average fiber diameter of the target sample. In particular, when fibers having two types of fiber diameters, each having a weight average fiber diameter of R ₁ and R ₂ , are mixed at a weight fraction of f ₁ : (1-f ₁ ), the weight average fiber diameter R _w can be expressed by the following equation.
_{R w = R 1 × f 1} + R 2 × (1-f 1)

(2) Weight per unit area The evaluation of the basis weight of the nonwoven fabric structure was calculated according to P-8124.
(3) Tensile strength / elongation The tensile strength was evaluated according to a method defined in JIS P 8113, using a desktop horizontal tensile tester (No. 2000) manufactured by Kumagaya Riki Kogyo Co., Ltd., and a sample having a width of 15 mm. Ten points were measured, and the average value was taken as the tensile strength and elongation. Considering the difference in basis weight, the strength was evaluated by a value corresponding to 10 g / m ² basis weight.
(4) Thickness measurement method The thickness of each nonwoven sheet was measured at 10 points in the width direction with an automatic micrometer manufactured by Hibridge Corporation in an atmosphere of room temperature 20 ° C. and humidity 65% RH. The average value was taken as the thickness of the nonwoven fabric structure.

(5) Zeta potential evaluation method The surface zeta potential of the surface of the nonwoven fabric structure was measured using Zeta Sizer Nano ZS ^TM manufactured by Spectris. As measurement conditions, flat cell ZEN1020 is used as a measurement cell, 1 to 1.5 ml of potassium chloride 0.01 mol / L aqueous solution is used as a measurement solvent, latex particles charged negatively or titanium oxide charged positively is used as tracer particles. Particles were used. The sample was cut in advance, and when a fine cellulose fiber layer was included, it was affixed to the cell with a double-sided tape so that the fiber layer surface would be the measurement surface. The measurement was performed at 25 ° C.

(6) Face mask wearing feeling evaluation method (Part 1)
A 40-year-old woman made a face mask that was impregnated with 1000 parts by weight of moisturizing liquid (Kanebo Cosmillion Co., Ltd. Ururi) for 100 parts by weight of a non-woven structure punched into a certain face shape. Ten panelists were allowed to wear, and sensory evaluation was performed for the close contact feeling, the touch, the wrapping feeling, and the handleability at the time of wearing. In addition, each evaluation was evaluated on a 5-point scale, and the average value of 10 people (rounded off after the decimal point) was calculated.
5 points: Excellent adhesion, touch, handling, and wrapping.
4 points: Good adhesion, feel, handleability, and wrapping feeling.
3 points: There is no problem in the feeling of adhesion, touch, handling, and feeling of wrapping.
2 points: Slightly inferior to the touch, feel, handling and wrapping.
1 point: Adhesion, touch, handling, and wrapping are poor.

(7) Face mask wearing feeling evaluation method (2)
The lift-up feeling was evaluated as an evaluation method similar to the face mask wearing feeling evaluation method (part 1) and the number of panelists. However, the lift-up feeling evaluation method was performed as follows.
After wearing a face mask impregnated with moisturizing liquid, both ends of both cheeks are stretched about 15-25% in the direction of 30 ° with respect to the vertical direction of the face with both hands, The cheek lift feeling (lifting feeling) was sensory-evaluated according to the following criteria.
5 points: Excellent lift-up feeling.
4 points: Lift up feeling is good.
3 points: I feel a little lifted up.
2 points: Little lift-up feeling is felt.
1 point: No lift-up feeling is felt.

Example 1
Abaca Pulp (manufactured by Nippon Paper Pulp Co., Ltd., IRR40) is immersed in water to 10% by weight, heat treated in an autoclave at 130 ° C. for 4 hours, and the resulting swollen pulp is washed with water many times. A swollen pulp impregnated with water was obtained.
The swollen pulp is dispersed in water to a solid content of 1.5% by weight to form a water dispersion (400 L), and a SDR14 type laboratory refiner (pressure type DISK type) manufactured by Aikawa Tekko Co., Ltd. is used as the disc refiner device. The beating treatment was continued for 20 minutes on the 400 L aqueous dispersion with a clearance between the disks of 1 mm, and then the beating treatment was continued under the condition that the clearance was reduced to almost zero. Sampling was carried out over time, and the CSF value of the Canadian standard freeness test method (hereinafter referred to as CSF method) of pulp defined by JIS P 8121 was evaluated for the sampling slurry. Then, once it was close to zero, if the beating process continued further, a tendency to increase was confirmed. The beating treatment was continued under the above conditions for 60 minutes after the clearance was reduced to near zero, and a beating slurry having a CSF value of 640 ml ↑ was obtained. The obtained beating slurry was subjected to a micronization treatment 5 times under an operating pressure of 100 MPa using a high-pressure homogenizer (NS015H manufactured by Niro Soabi (Italy)) as it was, and micronized cellulose fibers (microfibrillated cellulose) An aqueous dispersion M1 (solid content concentration: 1.5% by weight) was obtained. M1 was diluted with ion-exchanged water to a solid content concentration of 0.06% by weight, and then dispersed with a home mixer for 4 minutes to obtain a diluted dispersion of M1. The diluted dispersion was stirred with a motor with a stirrer under stirring at about 300 rpm for 3 minutes, and the obtained aqueous dispersion M2 was used as a papermaking dispersion described below.

The size of a square metal wire (25 cm) used for a plain fabric made of PET / nylon blend (Shikishima Kanbus Co., Ltd., NT20, water permeation amount at 25 ° C. in air: 0.03 ml / cm ² · s). × 25cm), a cupra rayon non-woven fabric (Asahi Kasei Co., Ltd.) on the filter cloth in a batch type paper machine (manufactured by Kumagai Riki Kogyo Co., Ltd., automatic square sheet machine 25cm × 25cm, 80 mesh). Product name: Benrize ^™ SE-603, basis weight 60 g / m ² , film thickness 400 μm, density 0.15 g / cm ³ , average single yarn fineness 2 dtex), and fine cellulose with a basis weight of 3 g / m ² Using the fiber nonwoven fabric layer as a guide, the paper dispersion prepared above is added, and then papermaking (dehydration) is carried out at a reduced pressure with respect to atmospheric pressure of 4 KPa. Obtained. The weft elongation of the cupra rayon nonwoven fabric (SE603) used above in a wet state was 25%.
The same filter cloth is put on the laminate of the obtained laminate wet paper and filter cloth, pressed at a pressure of 1 kg / cm ² for 1 minute, and then the laminate wet paper sandwiched from both sides by the filter cloth is removed. The laminated nonwoven fabric structure S01 including a white and uniform fine cellulose fiber nonwoven fabric layer is dried by a drum dryer set at a surface temperature of 130 ° C. for about 120 seconds, and finally the filter cloth on both sides is peeled off. Got.

When the surface of the obtained nonwoven fabric structure was subjected to SEM image analysis at a magnification of 10,000 times, no fine cellulose fibers exceeding 2000 nm were observed on the surface of the fine cellulose fiber nonwoven fabric layer, and the weight average fiber diameter was 0.00. It was 045 μm. The characteristics of S01 are shown in Table 1.
With respect to 100 parts by weight of the nonwoven fabric structure, a chemical solution-impregnated sheet S11 in which 1000 parts by weight of “Kanebo Cosmillion Ururi” as a chemical solution was introduced into the bat and impregnated in the nonwoven fabric structure was prepared. . Performance evaluation was carried out by the face mask wearing feeling evaluation method described above for S11, and the results shown in Table 2 were obtained. S11 was found to be a face mask with excellent adhesion, touch performance and handleability.

(Example 2)
The dispersion for papermaking prepared in Example 1 was introduced on the basis of the formation of a fine cellulose layer having a basis weight of 1 g / m ² on the same cupra rayon nonwoven fabric (SE-603) as in Example 1. In the same manner, a laminated nonwoven fabric structure S02 including a white and uniform fine cellulose fiber nonwoven fabric layer was obtained. The characteristics of S02 are shown in Table 1. About S02, the chemical | medical solution impregnation sheet | seat S12 was prepared by the same weight ratio as Example 1 using the same chemical | medical solution as Example 1. FIG. Performance evaluation was performed by the face mask wearing feeling evaluation method described above for S12, and the results shown in Table 2 were obtained. S12 was found to be a face mask with excellent adhesion, touch and handling.

(Example 3)
Using the papermaking dispersion prepared in Example 1, a cupra rayon nonwoven fabric (manufactured by Asahi Kasei Fibers, trade name: Benrize ^™ SE-804, basis weight 80 g / m ² , film thickness 480 μm, density 0.17 g / cm ³ , average single Paper is made on the basis of the formation of a fine cellulose fiber nonwoven fabric layer having a basis weight of 3 g / m ² on the yarn fineness 2 dtex), and is then laminated in the same manner as in Example 1 with white and uniform fine cellulose fiber nonwoven fabric. A nonwoven fabric structure S03 was obtained. In addition, the weft elongation in the wet state of the cupra rayon nonwoven fabric (SE804) before laminating | stacking with a fine cellulose fiber was 35%. The characteristics of S03 obtained are shown in Table 1. About S03, the chemical | medical solution impregnation sheet | seat S13 which used the same chemical | medical solution as Example 1 and was impregnated by the same weight ratio as Example 1 was prepared. Performance evaluation was carried out by the face mask wearing feeling evaluation method described above for S13, and the results shown in Table 2 were obtained. S13 not only has excellent adhesion, touch and handling, but also the lift-up performance was sensory evaluated by extending the cheek end sheets by about 20% in the direction of 45 ° when wearing a face mask. It turned out to be an excellent face mask.

Example 4
A hydroentangled nonwoven fabric produced by the following method was used in place of the cupra rayon nonwoven fabric used in Example 1, and a fine cellulose fiber nonwoven fabric layer having a basis weight of 3 g / m ² was formed on this hydroentangled nonwoven fabric in the same manner as in Example 1. The laminated white and uniform nonwoven fabric structure S04 was obtained. The hydroentangled nonwoven fabric was hydroentangled with a semi-random card web made of rayon fibers having a fiber length of 40 mm and a fineness of 1.7 dtex to obtain a hydroentangled nonwoven fabric having a basis weight of 40 g / m ² (film thickness 270 μm, density 0 .15 g / cm ³ ). The characteristics of S04 obtained are shown in Table 1. About S04, the chemical | medical solution impregnation sheet | seat S14 which was made to impregnate to the impregnation saturation amount using the same chemical | medical solution as Example 1 was prepared. Performance evaluation was carried out by the face mask wearing feeling evaluation method described above for S14, and the results shown in Table 2 were obtained. S14 was found to be a face mask with good adhesion, touch and handling.

(Example 5)
After adding ion-exchanged water to the aqueous dispersion M1 produced by the same method as in Example 1 so that the solid content concentration is 0.1% by weight and preparing a 300 L stock solution in the tank, the same disk as in the Example Using a refiner apparatus, the clearance between the disks was set to 0.5 mm, and dispersion treatment was performed for 20 minutes to obtain a papermaking dispersion.
Example of JP 2011-42903 A using an inclined wire type continuous paper making apparatus (manufactured by Saito Iron Works Co., Ltd.) having a width of 0.65 m and an inclination angle of 5 ° using the paper dispersion. A wire equivalent to the multilayered wire B10-MW2 disclosed in the above is attached, and a cupra rayon nonwoven fabric (manufactured by Asahi Kasei Fibers Co., Ltd., trade name: Benlyse ^TM NE-11G, basis weight 110 g / m ² , a film thickness of 430 μm, a density of 0.26 g / cm ³ , an average single yarn fineness of 2 dtex, a width of 0.80 m), and a papermaking dispersion obtained above at a feeding rate of 15.6 L / min. The paper was continuously fed from the stock solution feed tank, the paper running speed was 8.0 m / min, and the wet suction (inclined part) and the dry suction were operated to carry out continuous paper making. A press dehydration step using a metal roll was provided immediately after papermaking, and the cellulose concentration of the wet paper immediately after this step was 20% by weight. Continuously laminated non-woven fabric structure wet paper is dried with a drum dryer whose surface temperature is set to 105 ° C., and a white and uniform continuous non-woven fabric structure in which fine cellulose fiber nonwoven fabric layers having a basis weight of 5 g / m ² are laminated. S05 was wound up in a roll (about 100 m). In addition, the weft elongation in the wet state of the cupra rayon nonwoven fabric (NE11G) before laminating | stacking with a fine cellulose fiber was 40%. The properties of S05 obtained are shown in Table 1.
About S05, the same chemical | medical solution as Example 1 was used, and the chemical | medical solution impregnation sheet | seat S15 impregnated to the impregnation saturation amount was prepared. Performance evaluation was carried out by the face mask wearing feeling evaluation method described above for S15, and the results shown in Table 2 were obtained. It was found that S15 is a face mask that has excellent adhesion, handleability, and touch performance, and also has an excellent lift-up feeling.

(Example 6)
In Example 1, polydiallyldimethylammonium chloride (PDADMAC), which is a water-soluble polymer containing a quaternary ammonium salt, was dispersed in a household mixer with an aqueous dispersion of fine cellulose fibers having a solid content concentration of 0.06% by weight. , Manufactured by Nittobo Medical, PAS-H-10L, average molecular weight 200,000) is mixed as a 1% aqueous solution by weight of 0.2% by weight with respect to fine cellulose fibers, and stirred at about 300 rpm with a motor equipped with a stirrer. The mixture was stirred for 3 minutes, and the resulting aqueous dispersion was used as a papermaking dispersion described below. The paper was then laminated on a cupra rayon nonwoven fabric SE603 under the same conditions as in Example 1, and the basis weight was 3 g. / m ^2, and white fine cellulose fiber nonwoven layer zeta potential is controlled to + 50 mV are stacked To obtain a uniform nonwoven structure S06. The characteristics of S06 obtained are shown in Table 1. About S06, the chemical | medical solution impregnation sheet | seat S16 which used the same chemical | medical solution as Example 1 and was impregnated by the same weight ratio was prepared. Performance evaluation was carried out by the face mask wearing feeling evaluation method described above for S16, and the results shown in Table 2 were obtained. S16 was found to be a face mask with better adhesion, handling performance, and touch performance by controlling the contact surface with the skin to the positive side of the zeta potential.

(Example 7)
In Example 1, instead of Abaca pulp, Tencel ^TM shortcut fiber (manufactured by Lenzing Fibers Co., Ltd., 3 mm long cut product) was used as a raw material, and after the same purification process as in Example 1, the same beating treatment was performed, and the CSF value To 80 ml ↑ of beating slurry (solid content concentration: 1.5% by weight). The obtained beating slurry was subjected to a refining treatment twice under an operating pressure of 100 MPa using a high-pressure homogenizer as it was, and an aqueous dispersion (solid content concentration: 1.5) of finely divided cellulose fibers (microfibrillated cellulose). % By weight). The aqueous dispersion is diluted with ion-exchanged water to a solid content concentration of 0.06% by weight, then dispersed for 4 minutes with a home mixer, and further stirred for 3 minutes with stirring at about 300 rpm by a motor with a stirrer. Then, a papermaking dispersion was prepared. A white and uniform nonwoven fabric structure in which a fine cellulose fiber nonwoven fabric layer having a basis weight of 3 g / m ² is laminated on the cupra rayon nonwoven fabric SE603 under the same papermaking conditions as in Example 1 using the paper dispersion. Body S07 was obtained. The characteristics of S07 obtained are shown in Table 1. The fiber diameter of the fine cellulose fibers constituting the fine cellulose fiber layer was 0.81 μm by SEM analysis. About S07, the chemical | medical solution impregnation sheet | seat S17 which used the same chemical | medical solution as Example 1 and was impregnated by the same weight ratio was prepared. Performance evaluation was performed by the face mask wearing feeling evaluation method described above for S17, and the results shown in Table 2 were obtained. S17 was found to be a face mask with good adhesion, handling and touch performance.

(Example 8)
The same as in Example 1 except that a cupra rayon nonwoven fabric (made by Asahi Kasei Fibers, trade name: Benrize ^™ SE384, basis weight 38 g / m ² , film thickness 280 μm, density 0.14 g / cm ³ , average single yarn fineness 2 dtex) is used. Under the conditions, a nonwoven fabric S08 in which a fine cellulose fiber nonwoven fabric layer (weight per unit: 3 g / m ² ) was laminated was obtained. The characteristics of the obtained S08 are shown in Table 1. About S08, the chemical | medical solution impregnation sheet | seat S18 which used the same chemical | medical solution as Example 1 and was impregnated by the same weight part ratio was adjusted. Performance evaluation was performed by the face mask wearing evaluation method described above for S18, and the results shown in Table 2 were obtained. S18 was found to be a face mask with excellent adhesion and touch performance and excellent handling performance even though the nonwoven fabric structure has a low basis weight of 41 g / m ² . The weft elongation of the cupra rayon nonwoven fabric (SE384) used above in a wet state was 30%.

(Comparative Examples 1-5)
As a comparative example of Example 1 to Example 7, using R01: SE603 itself, R02: SE804 itself, R03: Spunlace of Example 4, R04: NE11G, R05: SE384 itself, a chemical solution impregnated sheet was prepared, Performance evaluation was performed. The characteristics of R01 to R05 are shown in Table 1. About R01-R05, the same chemical | medical solution as Example 1 was used, and the chemical | medical solution impregnation sheet | seat R11-R15 impregnated by the respectively same weight ratio was prepared. Performance evaluation was carried out by the face mask wearing feeling evaluation method described above for R11 to R15, and the results shown in Table 2 were obtained. It was found that R11 to R15 are face masks that are clearly inferior in adhesiveness as compared to the sheet in which the corresponding fine cellulose fiber layers are laminated.

(Comparative Example 6)
Prepared to have a weight average fiber diameter of 2 μm by mixing with wood pulp (weight average fiber diameter: 12 μm) and an aqueous dispersion M1 containing fine cellulose fibers (weight average fiber diameter of contained fibers: 0.045 μm) (fiber The mixing ratio of the wood pulp fiber was 16% by weight and the fine cellulose fiber was 84% by weight) to obtain a papermaking dispersion. Using the obtained papermaking dispersion, a mixed papermaking fiber layer was laminated on SE603 to obtain R06 which was white and slightly lacking uniformity. The properties of the obtained R06 are shown in Table 1. About R06, the chemical | medical solution impregnation sheet | seat R16 which used the same chemical | medical solution as Example 1 and was impregnated to the impregnation saturation amount, respectively was prepared. It was confirmed by surface SEM analysis of R16 that a fine cellulose fiber nonwoven fabric layer having a fiber diameter of 2.0 μm was formed on the surface almost as designed. Performance evaluation was performed by the face mask wearing feeling evaluation method described above for R16, and the results shown in Table 2 were obtained. R16 was not a sheet that functioned as a face mask because a number of dropped fiber residues remained on the face after application to the face.

  According to the present invention, a non-woven fabric structure having exceptionally high adhesion at the time of wearing, excellent touch performance, feeling of wrapping, handling performance, lift-up performance, and excellent cosmetic liquid retention and chemical penetration into the skin, and It is possible to provide a chemical liquid impregnated sheet represented by a face mask using the structure.

Claims (7)

  On one or both surfaces of the nonwoven fabric layer containing cellulosic fibers, a fine cellulose fiber nonwoven fabric layer is laminated in at least one layer or multiple layers, and the nonwoven fabric structure integrated with the nonwoven fabric layer containing cellulosic fibers is impregnated with a chemical solution. An average fiber diameter of the fine cellulose fibers forming the fine cellulose fiber nonwoven fabric layer is 0.01 μm or more and 1.5 μm or less, and the fine cellulose fiber nonwoven fabric layer is a contact surface with the skin. A chemical solution impregnated sheet. ^2. The chemical liquid impregnated sheet according to claim 1, wherein the total basis weight of the fine cellulose fiber nonwoven fabric layer is 0.5 g / m ² or more and 6 g / m ² or less.   The chemical liquid-impregnated sheet according to claim 1 or 2, wherein the nonwoven fabric layer containing cellulosic fibers is a nonwoven fabric layer made of regenerated cellulose fibers and / or natural cellulose fibers.   The chemical liquid-impregnated sheet according to claim 3, wherein the nonwoven fabric layer containing cellulosic fibers is a nonwoven fabric layer composed of regenerated cellulose continuous long fibers.   The surface of the contact surface with the skin has a zeta potential in the range of -250 mV to +250 mV, wherein a substituent having a charge is immobilized on the surface of the fine cellulose fiber nonwoven fabric layer. The chemical | medical solution impregnation sheet | seat as described in any one of these.   The chemical | medical solution impregnation sheet | seat as described in any one of Claims 1-5 in which 100-2000 weight part chemical | medical solution is impregnated with respect to 100 weight part of nonwoven fabric structures.   The face mask which consists of a chemical | medical solution impregnation sheet | seat as described in any one of Claims 1-6.