JP4937603B2 - Fiber sheet and pack cosmetics - Google Patents

Description

  The present invention is a collagen fiber sheet that has a very low metal impurity content, has a good touch and is easily dissolved in an aqueous liquid, and is formed using the same, and is easy to apply to and remove from the skin and has a long moisture retention. It relates to a pack cosmetic that is maintained.

  Pack cosmetics are cosmetics in which various active ingredients are blended into a pack base, and the active ingredients are supplied to the skin by applying to the skin and holding for a predetermined time. Conventional pack cosmetics are roughly classified into a washing type that is washed off after use, and a peeling type that forms and peels off a film. In the case of a washing-type pack cosmetic, the pack base is creamy, viscous liquid, foamy, etc., and is applied to the skin and left standing, and then washed off with water or lukewarm water or wiped with a wet towel. In the case of the peeling type, the pack base is in the form of a jelly, paste or viscous liquid, and after being applied to the skin, a film is formed by drying or the reaction of the base. Cosmetics can be peeled off by hand. From the viewpoint of labor after use, the peel type tends to be preferred by general users over the cleaning type.

In recent years, facial mask-type pack cosmetics in which a cosmetic ingredient is included in a non-woven fabric base have been provided as a new type, and this type of pack cosmetics requires no worry about peeling off. Depending on the condition, the pack cosmetic can be peeled off at any time. For example, Patent Document 1 below proposes a cosmetic in which a non-woven cosmetic component is contained in a nonwoven fabric, and Patent Document 2 below proposes a cosmetic device in which a dry water-soluble moisturizing component is attached to the surface of the cotton body. Has been.
JP 2004-51521 A JP 2002-255726 A

  When collagen is introduced into a facial mask type pack cosmetic, collagen having low thermal stability in a solution state needs to be included in the substrate in a dry state in order to prevent its alteration.

  However, when a non-woven fabric or cotton is used as a base material and an aqueous collagen solution is impregnated or applied to the base material and dried, the dried collagen coats the fibers constituting the base material in a thick film shape, and thus impedes water absorption of the base fiber. As a result, the water retention amount of the mask as a whole is significantly reduced. Therefore, even if water is added to the mask, it dries in a short time due to insufficient water retention when it is applied to the skin, and does not exhibit a satisfactory moisturizing function. In addition, the surface area of the collagen thick film in contact with water is insufficient, and the dissolution rate of collagen becomes extremely slow. Since the amount of collagen dissolved also decreases due to insufficient water absorption of the base fiber, a sufficient amount of collagen cannot be applied to the skin. When a large amount of collagen is placed on the substrate, the solubilized collagen solidified while adhering to the substrate fiber impairs the flexibility of the substrate fiber, so that the touch is very bad and the mask is hard and difficult to handle.

  In recent years, from the viewpoint of irritation to the skin such as allergies, those that act directly on the skin have been required to be gentle to the skin. About components that show irritation to the skin such as metal impurities and poor touch. Is preferably suppressed as much as possible.

The object of the present invention is to firstly solubilize insolubilized collagen, to produce solubilized collagen and subsequently to produce solubilized collagen fibers.
A second object of the present invention is to provide a soluble collagen fiber sheet rather than solubilized collagen fibers.
The subject of this invention is providing the pack cosmetics which consist of a laminated body which combined the soluble collagen sheet of a specific structure, and the moisture-proof sheet | seat of a specific structure 3rdly.

The ultimate problem of the present invention is to provide a pack cosmetic that has a good touch in the presence of water, has little irritation to the skin, and is easy to handle.

  In order to solve the above-mentioned problems, the present inventors have made extensive studies, and as a result, can create a sheet having a good touch using solubilized collagen fibers, and apply this to use as a pack cosmetic. Thus, the present inventors have found that it is possible to provide a pack cosmetic that has a high moisturizing function, has a good touch and is easy to handle when applied to the skin, and has completed the present invention.

The present inventors have found the following and solved the above problems.
(1) The isoionic point of the collagen aqueous solution obtained by solubilizing the collagen is a solubilized collagen aqueous solution adjusted to pH 5.0 to 8.0 higher than the pH, and the solubilized collagen aqueous solution is spun. A solubilized collagen fiber sheet can be obtained if the solubilized collagen fiber is formed and the basis weight is 5 to 50 g / m ² .
(2) The solubilized collagen fiber sheet according to (1), wherein the solubilized collagen fiber obtained by spinning the solubilized collagen aqueous solution is obtained by spinning in an alcohol solvent.
(3) The solubilized collagen fiber obtained by spinning the solubilized collagen aqueous solution is a solubilized collagen fiber obtained by spinning in an isopropanol solvent, and its metal content is an ash content measuring method according to JIS K6503: 2001 (1) as described in (1), wherein the ash content is 5% by mass or less and Na is 2% by mass or less as measured by atomic absorption spectrophotometry, and the basis weight is 5 to 50 g / m ² . Solubilized collagen fiber sheet.
(4) The solubilized collagen fiber sheet according to (1), wherein the solubilized collagen fiber has a fineness of 40 dtx or less.
(5) The solubilized collagen fiber sheet according to (1), wherein the solubilized collagen fiber sheet is a non-woven fabric made of solubilized collagen short fibers having a fiber length of 0.5 to 20 mm.

Moreover, according to one aspect of the present invention, the pack cosmetic is composed of solubilized collagen fibers having an ash content of 5% by mass or less and an isoionic point of pH 5.0 or less by an ash measurement method, and the basis weight is 50 g / m ^2. It has the fiber sheet which is the following, and the moisture-proof sheet laminated | stacked on the said fiber sheet, and makes it a summary to have the water-permeable hole which can supply water to the said fiber-proof sheet.

  According to the present invention, a soft and comfortable fiber sheet can be prepared using solubilized collagen fibers, and it is easy to handle and exhibits a sufficient moisturizing function for a long time. It is possible to provide a pack cosmetic that is easy to process and has a low burden on the skin. In addition, collagen can be quickly dissolved using commercially available lotion, etc., and collagen can be efficiently supplied to the skin in an optimal state that meets the needs of each user, and the product specifications are subdivided. It can be widely provided to various users without doing so.

  Collagen is a major protein that forms animal skins, tendons, bones, etc., and is a substance in which three polypeptide chains are formed in a helix, usually against water, dilute acid, dilute alkali, organic solvents, etc. Although it is insoluble, a solubilized aqueous collagen solution can be obtained by solubilization treatment. For the solubilization treatment, a method using a proteolytic enzyme (see, for example, Japanese Patent Publication No. 44-1175, hereinafter referred to as an enzyme treatment method), a small amount of amines in an aqueous solution in which caustic alkali and sodium sulfate coexist or It can be roughly classified into a method of treating with a substance added with an analog (for example, refer to Japanese Examined Patent Publication No. 46-15033, hereinafter referred to as an alkali treatment method). It is considered that the binding between peptide chains is released by cross-linking or cleavage of the telopeptide itself and solubilized.

  In recent years, makeup products, skin care products, and the like in which collagen is blended as a component for enhancing the moisture retention property of skin using the moisture retention property of collagen have been provided. Collagen used in such an application is solubilized collagen, and the aqueous solution of solubilized collagen becomes a solid dried product when water is removed. The denaturation start temperature of solubilized collagen in an aqueous solution is very low, about 30 ° C. for cows and pigs, and about 20 ° C. for puffer fish, tie, etc. In this case, the temperature is around 100 ° C., and there is no risk of degeneration during normal handling. Moreover, unlike the aqueous solution, the collagen in a dry state has no fear of spoilage.

  When a porous material having water absorption ability and water retention ability such as non-woven fabric or cotton is used as a base material and impregnated or coated with a solubilized collagen aqueous solution, the surface of the base fiber is covered with solidified collagen. This impedes water absorption and significantly reduces water retention capacity. Moreover, the softness | flexibility of a base fiber will be impaired by the solubilized collagen solidified material which coat | covers, and the touch will deteriorate remarkably. Moreover, since the water absorbed by the collagen when the water is supplied is taken away by the base fiber, the dissolution of the collagen is delayed, so it takes time to become suitable for use, and the function of moisturizing the skin is also achieved. It is difficult to demonstrate.

  Compared to this, when a fiber sheet made of solubilized collagen is produced using solubilized collagen fibers as raw fibers, a flexible and soft fiber sheet is obtained, and the collagen fibers are entangled without using base fibers. Can prevent the fibers from falling off. When this is used as a pack cosmetic, it quickly dissolves upon supply of water to form a gel-like collagen aqueous solution, so that the touch is always good and there is little irritation to the skin. The supply of water quickly brings about a state suitable for the pack, and only the collagen solution is produced. Therefore, there is no residue of the base fiber or film-formed product after use, and it is only necessary to remove the excess collagen. Therefore, cleaning and wiping work after use becomes very simple, and the burden on the skin due to friction and the like is reduced in this respect as well. Therefore, a flexible fiber sheet formed of solubilized collagen fibers is very useful as a pack cosmetic.

  When water is supplied to a fiber sheet made of solubilized collagen fibers on the skin to produce an aqueous solution, the moisture evaporates due to body temperature while acting on the skin as a pack cosmetic. . In order to prevent this, the pack cosmetic of the present application has a moisture barrier sheet laminated on the fiber sheet, and by covering the fiber sheet with this moisture barrier sheet, the transpiration of moisture from collagen on the skin is suppressed. To do. If a moisture barrier sheet is provided with many small-diameter through-holes that do not substantially affect the suppression of moisture transpiration, moisture can be replenished to the collagen from the outside of the moisture barrier sheet. No need to complete the supply. That is, collagen fibers can be sufficiently dissolved by replenishing water from the moisture barrier sheet side in contact with the skin after moistening the collagen fibers with an amount of water sufficient to maintain the shape of the fiber sheet. Therefore, it is possible to prevent the pack cosmetic from becoming non-uniform due to the collagen aqueous solution dripping or flowing when placed on the skin.

  Below, the form of the solubilized collagen fiber and fiber sheet which comprise the pack cosmetics of this invention is demonstrated.

  The solubilized collagen fiber that forms the fiber sheet is formed by forming collagen that has become soluble in water by the solubilization process into a fibrous form, and an aqueous solution of solubilized collagen is discharged into salt water or an organic solvent according to a known method. It can be prepared by coagulation and spinning. For example, it can be obtained by referring to the method for producing a dried solubilized collagen disclosed in JP-A-6-228505. In this application, in order to reduce irritation to the skin, solubilization obtained by a method of spinning a solubilized collagen aqueous solution in an organic solvent in consideration of easy reduction of the content of impurities such as metals. It is desirable to use collagen fibers. The metal impurities include Na, Ca, Mg, K, P and the like derived from collagen raw materials, but most are Na frequently used in the manufacturing process. In spinning by salting-out coagulation in salt water such as sodium sulfate, the amount of metal components derived from salt water adhering to and contained in the coagulated collagen fibers is large, and the tactile sensation is very poor. Moreover, in the washing with water, when the salt concentration is lowered, the collagen fibers are re-dissolved, so that the metal component cannot be sufficiently removed. Even when washing is performed with a mixture of water and an organic solvent in order to avoid re-dissolution, the washing efficiency is very low. In comparison, in spinning in an organic solvent, by using alcohol (particularly isopropanol) as a solvent, the metal salt contained in the collagen aqueous solution can be dissolved and removed in the solvent. A small amount of solubilized collagen fiber can be easily prepared, and the amount of organic impurities such as lipids is also reduced. In particular, when preparing a collagen fiber having a small diameter, the salt dissolution / removal efficiency is high. For example, when a solubilized collagen fiber of about 40 dtx or less (dtx: grams per 10000 m of fiber) is spun using isopropanol as the solvent, the metal content of the collagen fiber immediately after spinning is higher than that of the fiber spun by salting out coagulation. 1/10 or less. The metal content of the collagen fiber can also be evaluated by an ash content measurement method (measured as an inorganic oxide; see JIS K6503: 2001). According to this method, the ash content (%) of collagen fiber spun with isopropanol [= 100 × Residual mass after heat treatment (g) / sample mass (g)] is 10% or less, and 5% by mass or less can be easily obtained. In particular, it is easy to prepare a material having Na of 2% by mass or less (measured by atomic absorption spectrophotometry), which occupies most of the metal.

  Solubilized collagen having an isoionic point of about pH 5.0 or less as the solubilized collagen constituting the fiber sheet so that the solubilized collagen fibers are generally dissolved in water at the pH of cosmetics that are generally weakly acidic to near neutral. Is used. When such a solubilized collagen is prepared in an aqueous solution having a pH greater than the isoionic point and used for spinning, a solubilized collagen fiber having a high dissolution rate in weakly acidic to neutral water can be obtained. Those below about 10 dtx dissolve in water within 30 seconds. However, such fast solubility is not essential for pack cosmetics. In consideration of a decrease in the metal content contained in the coagulated collagen fibers, it is preferable to use a solubilized collagen aqueous solution adjusted to a pH of about 5.0 to 8.0 for spinning.

The fiber sheet may be a woven fabric or a non-woven fabric, and can be regarded as a fiber in which a general woven fabric or non-woven fabric is replaced with a solubilized collagen fiber. For pack cosmetics such as facial masks, the amount of solubilized collagen fibers (unit weight) per unit area of the sheet is preferably about 5 to 50 g / m ² . From the viewpoint of the flexibility and feel of the fiber sheet, it is preferable to use a solubilized collagen fiber having a fineness of 40 dtx or less, preferably 30 dtx or less, more preferably 20 dtx or less. A solubilized collagen fiber spun in an organic solvent has a fineness of about 30 dtx or less, particularly about 10 dtx or less, which is extremely flexible, has a very good feel in a sliver or web state, and has a low frictional resistance. Also suitable for.

  The woven fabric type fiber sheet can be manufactured using a spun yarn obtained by spinning solubilized collagen short fibers, a single yarn of solubilized collagen long fibers, or a twisted yarn obtained by twisting a plurality of long fibers, and these can be used alone or in combination. Can be used. A solubilized collagen fiber to be used can be appropriately selected according to the strength of the yarn required at the time of processing. In the present application, the woven fabric includes not only a narrowly-defined woven fabric using warp and weft but also a knitted fabric, that is, a long yarn. From the viewpoint of the strength of the fiber required at the time of processing, it is preferable to use a spun yarn, a twisted yarn, or a long fiber single yarn having a certain thickness. A fiber sheet knitted like a lace using thin solubilized collagen long fibers can appropriately reduce the amount of collagen per unit area, and when used as a pack cosmetic, the residual after use can be reduced.

Short fibers are generally used as the fibers for forming the nonwoven fabric, and the nonwoven fabric type fiber sheet in the present invention can be suitably produced using solubilized collagen short fibers. When the fiber length of the collagen fiber is about 0.5 to 20 mm, particularly about 1 to 5 mm, it is preferable in terms of workability in processing. The solubilized collagen short fibers constituting the nonwoven fabric are discharged using a stirring blade or the like when the solubilized collagen aqueous solution discharged in the organic solvent is solidified according to the previous application (Japanese Patent Application Laid-Open No. 2005-306736) by the applicant of the present application. It can be suitably produced by cutting a collagen fiber by applying a force in a direction crossing the direction, and in this production method, short fibers having an average fineness of about 3 dtx to 100 dtx are provided very simply. The average fiber length can be changed as appropriate by adjusting the solvent flow during spinning. Moreover, when preparing a thin short fiber of 10 dtx or less, you may cut | disconnect, after manufacturing a thin solubilized collagen long fiber according to the manufacturing method mentioned later. The solubilized collagen short fibers are dried and then defibrated and mixed using a carding machine or the like to obtain a uniform sliver, and the fibers are fastened and densified using a needle punch or the like to form a nonwoven fabric. A fiber sheet is formed. Alternatively, the nonwoven fabric may be formed by removing the solvent according to a wet papermaking method using a dispersion in which solubilized collagen short fibers obtained in JP-A-2005-306736 are uniformly dispersed in an organic solvent. In this method, a thin fiber sheet having a basis weight of about 5 to 50 g / m ² can be prepared. The thickness of the nonwoven fabric can be determined in consideration of the amount of solubilized collagen fibers per unit area, the flexibility of the fiber sheet, and the like according to the necessity in the usage form of the cosmetic.

In the production of a general nonwoven fabric, a binder that bonds fibers may be used. In the present invention, fibers can be bonded to each other by utilizing residual moisture contained in the collagen fibers after spinning. For example, when collagen short fibers spun in an organic solvent are crushed into a sheet by a wet papermaking method and then dried by a method such as air drying, a small amount of collagen remaining on the fiber surface is regenerated by the trace amount of water remaining after the organic solvent evaporates. By dissolving and drying the sheet in this state, the re-dissolved collagen solidifies and bonds the fibers. If the residual water content is insufficient, a small amount of water may be sprayed. When this adhesion method is applied, a nonwoven fabric made of collagen long fibers can also be produced. For example, a fiber bundle spun into ultrafine collagen fibers in an organic solvent is pulled out of the solvent in a state where the fiber bundle is thinly and evenly spread in an organic solvent, and the solvent is removed. After spreading the solvent and laminating the solvent, laminating the two fiber layers so that the fibers of the first layer and the fibers of the latter layer intersect, and drying by air drying or reduced pressure, the trace amount remaining in the stage where the organic solvent has evaporated The surface of the collagen fiber is redissolved by the moisture, and the layered fibers are bonded to each other by solidifying the redissolved collagen when sufficiently dried. When the remaining water is insufficient, a minute amount of water is sprayed to promote re-dissolution of the fiber surface. In this method, it is possible to produce a mesh-like non-woven fiber sheet with a very small basis weight, and it is possible to realize about 5 to 50 g / m ² per unit area, which is an appropriate amount of solubilized collagen fiber as a pack cosmetic. Become. The basis weight of the fiber sheet can be arbitrarily adjusted by the arrangement density of the fibers and the number of layers. It is not necessary for the directions of the fibers in one layer to be parallel to each other, and a fiber sheet in which short fibers and long fibers are laminated by combining wet paper making using collagen short fibers and long fibers arranged in layers is manufactured. You may do it.

  Below, the spinning method of a solubilized collagen fiber and the detail of the manufacturing method of a fiber sheet are demonstrated.

  Insoluble collagen can be suitably prepared by conventional methods using the skin of animals such as cows, pigs and birds, and other tissues containing collagen, and the raw material is not particularly limited. Insoluble collagen may be obtained from aquatic raw materials such as fish skin and fish scales. Although there is a difference in the denaturation temperature of collagen depending on the raw material from which collagen is obtained, there is no problem in ordinary handling in the dry state even if solubilized collagen derived from any raw material. In demand, it is preferable to use collagen derived from pigs or aquatic organisms as a raw material in relation to BSE countermeasures.

  Collagen raw materials such as cow skin and pork skin are prepared into raw material pieces of appropriate dimensions by performing treatment such as hair removal by lime pickling, water washing, shredding using a chopper, etc. Subject to solubilization treatment.

  Insoluble collagen is treated with a proteolytic enzyme (see, for example, Japanese Patent Publication No. 44-1175, hereinafter referred to as an enzyme treatment method), or a small amount of amines in an aqueous solution in which caustic alkali and sodium sulfate coexist. It can be solubilized by a method of treatment with an addition of the analog (see, for example, Japanese Patent Publication No. Sho 46-15033, hereinafter referred to as alkali treatment method). In the alkaline treatment method, aspartic acid residues and glutamine residues are changed to aspartic acid residues and glutamic acid residues by deamination reaction, respectively, so that the obtained solubilized collagen generally has an isoionic point of about 4.8-5. 0, and generally about pH 7 in the enzyme treatment method. When solubilized by an enzyme treatment method, it is necessary to shift the isoionic point of the resulting collagen from near neutral to pH 5 or lower. In solubilized collagen products by general enzyme treatment methods, succinylation is applied to lower the isoionic point to increase neutral solubility, so the solubilized collagen obtained by such methods is preferably used it can. The lower the solubilized collagen isoionic point, the higher the solubility in weakly acidic to neutral aqueous solvents. In order to increase the dissolution rate of collagen fibers used as cosmetics, the solubilized collagen isoionic point Is preferably about pH 4.8 or less.

  The solubilized collagen is obtained in the form of a viscous aqueous solution through neutralization of alkali used for solubilization and succinylation and desalting (for example, centrifugation, dialysis, washing with water, etc.). The method of coagulating a solubilized collagen aqueous solution in an organic solvent utilizes the fact that the collagen in the aqueous solution coagulates when it comes into contact with the organic solvent. In the previous application (Japanese Patent Application Laid-Open No. 2005-306736) by the present applicant, With reference to the method for producing dried solubilized collagen disclosed in Kaihei 6-228505, it has been proposed to prepare collagen fibers by discharging and solubilizing a solubilized collagen aqueous solution into a thread using a nozzle or the like. According to this method, the solubilized collagen aqueous solution having a fineness of about 40 dtx or less is dispersed in the organic solvent by discharging the solubilized collagen aqueous solution from the nozzle into the organic solvent according to this method and cutting the solubilized collagen being solidified with a stirring blade. To do.

  Specifically, as a spinning means for coagulating (that is, spinning) the collagen into a fibrous form, a means having a discharge hole capable of discharging a fluid such as a nozzle or a shower head is selected and used as necessary. In general, a solubilized collagen aqueous solution having a collagen concentration of 2 to 10% by mass, preferably 3 to 7% by mass, at a discharge speed of 20 to 500 g / min, preferably 30 to 150 g / min, and a pore size of 0.02 to 1 mm. Solubilized with an average fineness of about 3 to 100 dtx (value measured at 20 ° C. and 65% RH using a fineness meter). Collagen fibers are formed. In order to obtain short fibers having an average fineness of about 20 dtx or less, a nozzle having a discharge port diameter of about 0.2 mm or less is used, the concentration of the collagen aqueous solution to be discharged is 6 mass% or less, and the pH is about 5.5 to 8.0. It is preferable to adjust to.

  The solubilized collagen can be coagulated with either a hydrophilic organic solvent or a hydrophobic organic solvent, but a hydrophilic organic solvent is preferred in that it effectively dissipates the water contained in the coagulated collagen to the outside. In order to efficiently dry the fibers, a volatile solvent is preferable as an organic solvent for coagulating solubilized collagen. Examples thereof include alcohols such as methanol, ethanol and isopropanol, acetone, and the like, and may be a mixed solvent in which a plurality of such solvents are combined. Practically, an organic solvent containing a small amount of water can also be used. In that case, the moisture content is about 15% by mass or less, preferably 10% by mass or less. If the moisture content is high, collagen does not coagulate properly.

The organic solvent in which the solubilized collagen short fiber is spun contains water, and the metal component contained in the solubilized collagen aqueous solution used for spinning is released, so the metal content of the short fiber is considerably reduced. If the organic solvent is once removed by filtration or the like and then washed with a new organic solvent, impurities such as metals and lipids contained in the collagen fiber can be further reduced. In particular, isopropanol is preferably used as the organic solvent for spinning and the organic solvent for washing in view of dissolving the metal salt. The dispersion of the solubilized collagen short fibers after washing in an organic solvent forms a non-woven fiber sheet by using a papermaking net according to the wet papermaking method, and removes and dries the residual solvent by reduced pressure or air drying. As a result, a thin-leaf collagen fiber sheet is obtained. The basis weight of the fiber sheet can be adjusted as appropriate by adjusting the ratio of the area of the papermaking net to be used and the amount of the collagen fiber dispersion, and generally about 5 to 50 g / m ² can be easily obtained. The collagen short fibers can be bonded by a minute amount of moisture remaining after the organic solvent evaporates in the drying process. When the adhesion is insufficient, it may be dried again after spraying a small amount of water.

  In spinning in a free state, the fineness becomes higher than that during discharge due to shrinkage during coagulation, so the above method has a limit in forming thinner collagen fibers. Fine collagen fibers having a fineness of 10 dtx or less are obtained by drawing solubilized collagen fibers to be spun during coagulation. When producing fine collagen fibers with a fineness of about 10 dtx, the fibers tend to adhere and fuse together when drying the fibers so that they form a lump. If the spun collagen fibers are immersed in a hydrophilic organic solvent before drying, the fibers are dried. The adhesion of collagen fibers inside can be prevented. In order to obtain short fibers from such collagen long fibers, the collagen fibers before drying may be cut in an organic solvent.

  In the drawing spinning of solubilized collagen fibers, the collagen fibers to be spun are wound up at a speed higher than the discharge speed, and the fibers are drawn by a tensile force applied to the collagen fibers being spun. However, if the winding speed is too high, the fiber is cut, so that the ratio of the winding speed to the discharge speed is adjusted to 1.5 or less and stretched. The thickness of the solubilized collagen fiber can be reduced by lowering the concentration of the solubilized collagen aqueous solution to be discharged or by reducing the pore diameter of the nozzle to be discharged, but if the concentration of the solubilized collagen aqueous solution is too low The fiber to be spun is easily cut or a powdery coagulum is easily formed. On the other hand, if the nozzle hole diameter is too small, the liquid flow resistance increases and an excessive discharge pressure is applied to the nozzle. Taking these into consideration, preferred conditions for spinning collagen fibers having an average fineness of 10 dtx or less are 3 to 7% by mass, preferably 3.5 to 5% by mass, and the nozzle hole diameter is 0.02%. ˜0.18 mm, preferably about 0.05 to 0.11 mm, and the ratio of the winding speed to the discharge speed can be 1 or more and 1.5 or less, preferably 1.0 to 1.2. From the point of implementation, it is practical to set the discharge speed in the range of about 2 to 7 m / min and the winding speed in the range of about 2 to 10 m / min. The shape of the discharge hole that defines the cross-sectional shape of the fiber is not limited to a circle, but the discharge hole is deformed so that a solubilized collagen fiber having a complicated cross-sectional shape such as an ellipse, polygon, or star is formed. It is also possible to provide irregularities, notches, grooves and the like on the collagen fiber surface. However, it is necessary to consider that it becomes easy to cut | disconnect in extending | stretching. When the surface area of the fiber is increased, fast solubility in an aqueous solvent is improved.

  The wound solubilized collagen fiber is immersed in a hydrophilic organic solvent before drying, so that the moisture in the collagen fiber is dissipated into the organic solvent and replaced with the organic solvent. The amount of organic solvent increases and fiber adhesion during drying decreases. However, it is necessary that the hydrophilic organic solvent to be immersed has a low moisture content, and specifically, an organic solvent having a moisture content of 5% by mass or less is used. Examples of the organic solvent to be used include alcohols such as methanol, ethanol and isopropanol, and hydrophilic organic solvents such as acetone. A mixed solvent in which a plurality of such solvents are combined may be used. In order to avoid only water remaining when the collagen fibers are dried, it is effective to use a solvent having a boiling point close to that of water or a solvent azeotropic with water, and ethanol and isopropanol are preferable in this respect. Etc. The hydrophilic organic solvent may be gently flowed, or the solubilized collagen fibers soaked may be swung to promote the diffusion of moisture. Then, the solubilized collagen long fiber is obtained by drying by air drying using aseptic air or vacuum distillation.

  When manufacturing non-woven fiber sheets using solubilized collagen long fibers, a bundle of collagen fibers spun and stretched from a nozzle is spread in a thin layer in an organic solvent with residual moisture in the fibers. Then, using a papermaking net or the like, a desired number of fiber layers are stacked, lightly pressed or sprayed with moisture as necessary, and then dried. Thereby, since collagen fibers are adhere | attached by a trace amount non-coagulated collagen, the shape of a sheet | seat is maintained even if the fibers are not entangled.

  The dried solubilized collagen fiber contains about 10 to 20% by mass of water even in the standard state (20 ± 2 ° C., humidity 65 ± 2% RH), but the denaturation temperature is high, and the collagen derived from cattle and pigs is 100 ° C. Before and after.

  The fiber sheet of solubilized collagen obtained as described above is placed on the skin as it is and supplies moisture, so that the collagen quickly dissolves and exhibits a moisturizing function, but in order to prevent moisture transpiration due to body temperature, It is preferable to form a pack cosmetic by laminating on a sheet.

  The moisture shielding sheet is a flexible film formed by thinly forming a material that does not substantially transmit moisture. Fine-grained cloth and waterproof cloth that can substantially exhibit moisture barrier properties can also be used. When a light-transmitting film is used, the dissolution of the fiber sheet can be visually confirmed through the moisture shielding sheet, which is advantageous as a pack cosmetic and visually interesting. Considering applicability to a three-dimensional shape in a facial mask or the like, a soft plastic film is suitable. Examples of the material include polyolefins such as polyethylene and polypropylene; halogenated olefin polymers such as PVC, saran, PTFE, and polytrifluorochloroethylene; polyamides such as 6-nylon; terephthalic acid-based polyesters such as polyethylene terephthalate; polyurethane Isocyanate polymers, etc. can be used, and a film obtained by forming such a material into a layer according to a general method can be appropriately used. Although there will be no restriction | limiting in particular if the softness | flexibility of a moisture-shielding sheet is appropriate, Thickness is about 0.01-2 mm from the point of workability or a handling point.

  The moisture-proof sheet is preferably provided with a large number of minute water passage holes penetrating the sheet as long as the moisture-proof property is not lowered. The opening shape of the water passage hole is not particularly limited, and various shapes such as a circle, an ellipse, a polygon, and a star shape can be used, and a crack due to fracture may be used. A cross-shaped or star-shaped elongated opening shape is preferable in terms of both water flow and moisture barrier. In order to substantially maintain the moisture barrier property, the diameter (or opening width) of the water flow hole should be about 3 mm or less. Preferably, when the thickness is 0.05 to 1 mm, water is passed quickly by the action of capillary action, and processing is easy. The water passage holes may be formed before or after the fiber sheets are laminated, and can be formed by punching or puncturing by heat melting or the like. The density at which the water passage holes are provided, that is, the ratio of the total opening area of the water passage holes to the sheet area is preferably 10% or less, particularly about 0.05 to 5%.

  There is no particular limitation on the method of laminating the fiber sheet and moisture barrier sheet, but when the moisture-containing fiber sheet is stacked on the moisture barrier sheet and dried, the fiber sheet is lightly attached to the moisture barrier sheet and is easy to handle as a pack cosmetic. Become. The solubilized collagen aqueous solution may be used as a pressure-sensitive adhesive, and the fiber sheet may be bonded to the moisture-proof sheet. When using a pressure-sensitive adhesive, an adhesive may be partially applied and adhered to the sheet surface, such as in the form of spots or stripes. Alternatively, when a fiber sheet in a dry state is overlapped with a plastic film for a moisture-proof sheet prior to providing a water passage hole and perforated from the fiber sheet side using a perforation needle, a water passage hole is formed and collagen fibers of the fiber sheet are formed. Is introduced into the water passage hole by the perforating needle and extruded to the opposite side of the plastic film, so that the fiber sheet is supported on the moisture shielding sheet by the collagen fibers inserted into the water passage hole. And the movement of the water | moisture content supplied from the moisture-proof sheet | seat side is accelerated | stimulated by the collagen fiber which penetrates a water flow hole. The needle may be pulled back by perforating from the side of the plastic film using a perforated needle having retraction.

  The laminated moisture barrier sheet and fiber sheet can be handled well as a pack cosmetic by cutting into a size and shape suitable for the use site, if necessary. At the time of use, a small amount of aqueous liquid is sprayed from the fiber sheet side of the pack cosmetic to wet the fiber sheet, or the aqueous liquid is applied to the skin, so that the surface of the collagen fiber is adhered to the skin in a dissolved state. Then, by further supplying the aqueous liquid from the moisture shielding sheet side, the fiber sheet is replenished with moisture through the water passage holes of the moisture shielding sheet, and the entire collagen fibers are suitably dissolved. You may only supply an aqueous liquid from the moisture-proof sheet side to the pack cosmetics on skin, without moistening a fiber sheet. The method of supplying the aqueous liquid from the moisture shielding sheet side is not limited to spraying, and for example, a method in which moisture is contained in a sponge, cotton or the like and brought into contact with the moisture shielding sheet may be used. When the aqueous liquid is supplied so that the concentration of the collagen dissolved in the aqueous liquid is about 0.1 to 6% by mass, particularly about 0.1 to 3% by mass, the pack cosmetic is optimal. You may repeat addition of aqueous liquid as needed. After use, the moisture barrier sheet may be removed, and excess collagen on the skin may be appropriately removed by washing or wiping.

  The aqueous liquid for dissolving the collagen of the pack cosmetic may be a liquid mainly composed of water so that the pH in a state in which the collagen is dissolved deviates from the isoionic point of the collagen. Good. Although the solubility in pure water is reduced by the buffering action of collagen itself, it can be eliminated by the presence of electrolyte, and in consideration of irritation to the skin, electrolytes such as acids, bases, neutralization salts, buffer salts, etc. The solubility in an aqueous liquid is improved by appropriately selecting from the above and adding a small amount. A buffer salt (that is, a salt of a weak acid and a strong base) such as sodium citrate, sodium lactate, and sodium phosphate that stabilizes the pH to neutrality is added to adjust the pH of the aqueous solution to about 5.5 to 9.0. In this case, the solubility of the collagen fiber is stabilized, but the excessive salt makes the collagen difficult to dissolve in the aqueous liquid due to the salting out action. Even when the electrolyte is contained in the collagen fiber, the buffering action is reduced, and when a solubilized collagen aqueous solution containing the electrolyte is used in the preparation of the collagen fiber, a solubilized collagen fiber containing the electrolyte is obtained.

  In addition, various components that are generally added to cosmetics can be added to the aqueous liquid as needed, as long as they do not hinder the dissolution of collagen in the aqueous liquid. For example, butanediol, pentanediol, glycerol, hyaluron Moisturizers such as acids, preservatives (preservatives) such as methyl p-hydroxybenzoate and phenoxyethanol, plant extracts such as aloe extract, alcoholic solvents such as ethanol, ultraviolet absorbers, vitamins, anti-inflammatory agents, olive oil And various functional components having cosmetic effects.

  According to the requirements of the above-mentioned aqueous liquid, commercially available lotions and cosmetic liquids can also be used as the aqueous liquid. Therefore, the user can easily prepare a pack cosmetic by selecting a lotion or a cosmetic liquid according to preference and combining it with the fiber sheet. That is, it is possible to provide the user with a collagen pack cosmetic material that satisfies the user's needs in a fresh state as needed, and it can be adjusted to a suitable cosmetic material according to the skin quality of the user. Cold storage like conventional collagen cosmetics is also unnecessary.

  Collagen cosmetics after dissolution are easily denatured in the same way as ordinary aqueous collagen cosmetics, but the spinning of solubilized collagen fibers using alcohol has a bactericidal effect on collagen and is obtained after drying in sterile air Solubilized collagen fibers are not contaminated with bacteria. Moreover, the solubilized collagen in the dry state significantly suppresses the growth of bacteria and fungi compared to the solution state, so that the preservative treatment during distribution can be reduced, and no preservatives, preservatives, etc. are required. Become. Therefore, it can also be used as a pack cosmetic containing almost no ingredients other than collagen.

  The pack cosmetic of the present invention can be provided by being sold alone or in combination with an aqueous liquid that also serves as a basic cosmetic. You may provide an aqueous liquid with the container which attached | subjected the scale which shows the usage-amount of the aqueous liquid per time or 1 sheet | seat.

  Hereinafter, the fiber sheet and pack cosmetic of the present invention will be specifically described with reference to examples.

<Preparation of solubilized collagen>
The following operation was performed using 700 g of tilapia fish scales that had been deashed with hydrochloric acid, washed with water and dried as a collagen raw material.

  As a solubilizing solution, 8000 g of an aqueous solution containing 4.0% by mass of sodium hydroxide, 12.0% by mass of sodium sulfate and 0.7% by mass of monomethylamine was prepared, and the liquid temperature was kept at 20 ° C. The collagen raw material was immersed, stirred and mixed for about 1 minute, and well blended with the solubilized solution, and then allowed to stand for 10 days. Thereafter, while maintaining the liquid temperature at 18 to 20 ° C., 37.5% by mass sulfuric acid is gradually added to neutralize, and the pH is adjusted to 4.8 to bring the solubilized collagen into an isoelectric point precipitation state. A solubilized collagen piece retaining the raw material shape was obtained. After neutralization, the solubilized liquid was removed, and further lightly squeezed to extrude and remove the solubilized liquid contained inside.

  A lactic acid aqueous solution having a pH of 4.8 is prepared as a cleaning solution, and the collagen pieces are immersed in 10 L of the cleaning solution and stirred. After intermittently pressing lightly and repeatedly washing, the cleaning solution is removed and further compressed to be contained inside. The washing solution was pushed out and removed. Further, washing of the collagen piece with 10 L of the cleaning solution was repeated three times, and the cleaning solution was removed using a centrifugal dehydrator. The washed and desalted collagen pieces were air-dried using aseptic air to obtain 150 g of dried solubilized collagen. The dried soluble collagen was light tan and had a weak fishy odor. The isoionic point of the dried product was measured according to the following method and found to be pH 4.8. Further, the collagen content was measured by analysis by the Kieldar method. As a result, it was 96.6% by mass, the detected crude fat was 0.4% by mass, and the ash content (see the ash content measurement method of JIS K6503: 2001) was 1. It was 3 mass%. Based on this collagen content, the amount corresponding to the collagen mass of 120 g is separated from the desalted collagen piece, and water and sodium lactate are added and kneaded well so that the collagen concentration becomes 5.8 mass% and pH 7.1. As a result, 4000 g of a solubilized collagen aqueous solution was obtained.

(Measurement of iso-ion points)
The ratio of the cation exchange resin (Amberlite IPR-120B, manufactured by Organo Corp.) and the anion exchange resin (Amberlite IPA-400, manufactured by Organo Corp.), activated and washed in advance, in a ratio of 2: 5. To prepare a mixed bed ion exchanger. After equilibrating 100 ml of the mixed bed ion exchanger with deionized water, add 50 ml of the sample solution prepared so that the protein concentration becomes 5%, and keep gently in the water bath at 40 ° C. for 30 minutes. The supernatant was separated from the mixture and the pH of the supernatant was measured, and the value was taken as the isoionic point (refer to the method described in JW Janus, AW Kenchington and AGWard, Research, 4247 (1951)) .

<Preparation A of solubilized collagen fiber A>
Isopropanol (liquid temperature: 10 ° C.) is charged into the spinning bath, and a part of the soluble collagen aqueous solution is 41 g / min from the discharge hole (hole diameter: 0.18 mm, hole number: 700) directed vertically downward. The collagen was coagulated by discharging into isopropanol at a discharge speed of. At this time, the stirrer whose position is adjusted so that the tip of the stirring blade (four-sheet type) having a rotation radius of 5 cm passes about 3 mm below the discharge hole is operated, and the stirring blade is rotated at 280 rpm, so that isopropanol Fluidized. Thereby, isopropanol (dispersion concentration 0.8 mass%) in which the solidified solubilized collagen fibers were dispersed was obtained.

  The dispersion was filtered using a stainless steel net and then naturally dried to obtain soluble collagen fibers having an average fineness of about 28.6 dtx and a length (average) of 2.9 mm. The soluble collagen fibers were hardly colored and almost no odor was felt. When the collagen content of the soluble collagen fiber was measured, it was 91.5% by mass and the crude fat was 0.01% by mass. The ash content according to the ash measurement method of JIS K6503: 2001 was 4.1% by mass. The content of sodium occupying most of the metal was 1.2% by mass as a result of measurement by atomic absorption spectrophotometry.

  In addition, the fineness of the fiber is obtained by using an average value of the fineness measured by 20 per sample in an environment of 20 ° C. and 65% RH using a fineness meter (DENIEL COMPUTER DC-11A, manufactured by SEARCH CO. LTD). However, for short fibers of 4 cm or less, the following formula is used to calculate the fiber diameter measured at 60 points per sample in an environment of 20 ° C. and 65% RH using a digital microscope (VHX-100F, manufactured by Keyence). The average value calculated from the fineness determined according to the calibration curve is shown [where A is the fineness (dtx), a is the fiber diameter (μm), 0.0071 is the fiber diameter-fineness conversion factor, 1 .11 is the denier-decitex conversion factor].

A = 0.0071 × a ² × 1.11
<Preparation B of solubilized collagen fiber>
Solubilized collagen fibers were spun in the same manner as Preparation A of the solubilized collagen fibers except that 20 mass% aqueous sodium sulfate solution was added to the spinning bath instead of isopropanol. The spun solubilized collagen fibers were further washed by stirring in isopropanol / water (volume mixing ratio = 80/20, 25 ° C.) for 30 minutes, filtered and air-dried. As a result, a solubilized collagen fiber having an average fineness of about 8.2 dtx and a length (average) of 5 mm was obtained. This solubilized collagen fiber was found to have a large number of salt powders adhering to the surface, and was hard and not soft to the touch. When the collagen content of the soluble collagen fiber was measured, it was 44.9% by mass, the crude fat was 0.4% by mass, and the ash content was 48.9% by mass. The sodium content detected by atomic absorption spectrophotometry was 24.0% by mass. The sodium content of the solubilized collagen fiber obtained by increasing the number of washings with isopropanol / water to 5 times was 24.4% by mass, which was an error range value indicating that there was no washing effect. Met. Further, the solubilized collagen fibers swelled during washing, and the fiber strength was reduced.

<Preparation of aqueous solution of solubilized collagen>
Lime pickles were made from pork salted hides. Specifically, one piece of pork salted hide (about 4 kg) was cut into 3 cm square pieces, and 300% water and 0.6% nonionic surfactant were added to the mass. The skin pieces were washed by stirring and collected. Next, 300% water, 0.6% nonionic surfactant and 0.75% sodium carbonate were added to the skin mass and stirred for 2 hours to recover the skin. Further, after washing the collected skin piece twice with 700% water with respect to the skin piece mass, 300% water, 0.15% nonionic with respect to the skin piece mass. Surfactant, 3.6% sodium hydrosulfide, 0.84% sodium sulfide and 2.4% calcium hydroxide were added and stirred for 16 hours. Washing with 700% water was performed three times.

  8000 g of an aqueous solution containing 6% by mass of sodium hydroxide, 15% by mass of sodium sulfate and 1.25% by mass of monomethylamine was prepared, and 2000 g of the above-mentioned skin pieces (about 500 g as dry mass) were added and mixed with stirring. This was kept at 25 ° C. in a sealed container and incubated for 5 days to solubilize collagen. While the aqueous solution was gently stirred, the alkali in the aqueous solution was neutralized by dropwise addition of an equal amount of sulfuric acid to adjust the pH to 4.8. After the neutralized skin piece was taken out and squeezed to remove the liquid, the mixture was stirred for 30 minutes using about 8000 g of a lactic acid aqueous solution having a pH of 5.0, and then the skin piece was squeezed and dehydrated. This operation was repeated four more times for sufficient desalting. Collagen is solubilized because the skin is adjusted to a pH near the isoionic point of the solubilized collagen at the neutralization stage, but the shape of the skin is hardly dissolved even after desalting. Was holding.

  The collagen content of the skin after desalting is calculated from the result of total nitrogen measurement by the Kieldahl method. Based on this collagen content, the amount corresponding to the collagen mass of 120 g is separated from the skin after desalting, and the collagen concentration Water and sodium lactate were added and kneaded well so that the sodium lactate concentration was 1.2% by mass to obtain 4000 g of a solubilized collagen aqueous solution. Subsequently, the pH was adjusted to 6.7 by adding a small amount of a 20% by mass aqueous sodium hydroxide solution and kneading.

<Preparation of solubilized collagen fiber>
Using the solubilized collagen aqueous solution obtained above, the solubilized collagen fibers were spun in the same manner as in Preparation A of the solubilized collagen fibers of Example 1. A part of the spun solubilized collagen fiber was taken out from isopropanol and naturally dried to obtain a solubilized collagen fiber having an average fineness of about 13.4 dtx and a length (average) of 1 mm. The solubilized collagen fibers were hardly colored and almost no odor was felt. When the collagen content of the solubilized collagen fiber was measured, it was 92% by mass, the crude fat was 0.01% by mass, and the ash content was 2.6% by mass. The content of sodium occupying most of the metal was 0.7% by mass as a result of measurement by atomic absorption spectrophotometry. The isoionic point of the solubilized collagen fiber was pH 4.8.

In accordance with Preparation A of Solubilized Collagen Fiber of Example 1, a dispersion (dispersion concentration of 0.8% by mass) in which coagulated solubilized collagen fiber is dispersed in isopropanol is prepared, and a paper machine manufactured by Kumagai Riki Kogyo Co., Ltd. is used. This dispersion was paper-made and naturally dried to obtain a non-woven collagen fiber sheet having a length of 25 cm × width of 25 cm and a basis weight of 25 g / m ² .

A polyethylene film (thickness: 40 μm) having the same dimensions as the collagen fiber sheet is prepared, the fiber sheet is placed on a cushion brush covered with a cover film, the polyethylene film is overlaid, and a perforated needle having a turn (thickness: 0.00). 5 mm, needle density: 2.5 / cm ² ). As a result, in the polyethylene film, elongated holes (length: about 0.6 mm, width: about 0.3 mm) extending radially in three directions are formed by each punch needle, and a part of the collagen fibers of the fiber sheet is formed through the holes. Is pulled out to the opposite side of the polyethylene film to obtain a pack cosmetic in which the fiber sheet is fixed to the polyethylene film.

  After the pack cosmetic was stored in a constant temperature and humidity chamber (20 ° C., humidity 65%) for 24 hours, the pack cosmetic was taken out and its mass was measured. Then, deionized water was sprayed to such an extent that the fiber sheet was immersed, and the pack cosmetic was placed so that the fiber sheet was in contact with the stainless steel petri dish, and deionized water was sprayed on the polyethylene film (the total amount of water is the amount of collagen mass). However, it was observed that water transferred to the fiber sheet through the pores of the polyethylene film, solubilized collagen was dissolved and became jelly-like. After measuring the mass at this time, the stainless steel petri dish was kept on a 35 ° C. water bath for 1 hour (the surface temperature of the petri dish was 32 ° C.), the mass change was determined by mass measurement, and the ratio of the evaporated water was examined. It was 3 mass%. For comparison, water having the same size collagen fiber sheet placed on a stainless steel petri dish without a polyethylene film, dissolved in the same amount of deionized water as above, and similarly evaporated at 32 ° C. for 1 hour. The ratio was 89.3% by mass (average of two measurements).

  A medical pressure-sensitive adhesive sheet (length 3 cm × width 7 cm, opening area ratio: 0.25%) in which a pressure-sensitive adhesive was applied to a polyvinyl chloride film was prepared.

In accordance with the preparation of the solubilized collagen fiber of Example 2, a dispersion liquid (dispersion concentration of 0.8% by mass) in which the coagulated solubilized collagen fiber is dispersed in isopropanol is prepared using a paper machine manufactured by Kumagai Riiki Kogyo Co., Ltd. This dispersion was paper-made and naturally dried to obtain a non-woven collagen fiber sheet having a length of 25 cm × width of 25 cm and a basis weight of 25 g / m ² . The collagen fiber sheet was cut into the same dimensions as the medical pressure-sensitive adhesive sheet and pasted on the pressure-sensitive adhesive sheet to obtain a pack cosmetic.

  About the said pack cosmetics, like Example 3, it sprays deionized water, puts it on a stainless steel petri dish, observes the state change by supply of water, When the ratio of the transpiration water by leaving at 32 degreeC was investigated The solubilized collagen dissolved well and became jelly, and the ratio of the transpiration water was 34.6% by mass (average of two measurements).

  In addition, using a medical adhesive sheet having an opening area ratio of 2.5%, a pack cosmetic was prepared in the same manner as described above, and the ratio of the transpiration water at 32 ° C. of the pack cosmetic supplied with water was examined. It was 33.7% (average of two measurements).

  The concentration of the solubilized collagen aqueous solution used in the preparation of the solubilized collagen fiber of Example 1 was changed to 4% by mass, and the solubilized collagen fiber was prepared under the conditions 1 or 2 in Table 1 according to the process of preparation A of the solubilized collagen fiber. As a result of spinning, a fiber having a fineness of 6.9 dtx and a fiber length of 1.4 mm was obtained under Condition 1, and a fiber having a fineness of 3.6 dtx and a fiber length of 0.9 mm was obtained under Condition 2. For any of the fibers, a pack cosmetic could be prepared in the same manner as in Examples 3 and 4.

(Table 1)
Nozzle hole diameter / hole number Discharge speed Blade rotation speed Condition 1 φ0.10 mm / 1000H 45.6 g / min 280 rpm
Condition 2 φ0.05mm / 1000H 45.6g / min 250rpm

  A solubilized collagen aqueous solution derived from pig skin was prepared in the same manner as in Example 2 except that the amount of water used was adjusted so that the collagen concentration was 2% by mass. A solution obtained by adding 10% by mass of glycerin to the collagen aqueous solution and stirring and defoaming the solution is applied onto a PET film using a film forming machine and then air-dried at room temperature. The film was further insolubilized by UV irradiation to obtain an insoluble collagen film.

  The surface of the insoluble collagen film was wetted with water, and the nonwoven fabric-type solubilized collagen fiber sheet prepared in Example 3 was layered thereon and dried to laminate the insoluble collagen film and the solubilized collagen fiber sheet. Further, by performing punching using a piercing needle in the same manner as in Example 3, a pack cosmetic in which elongated holes in the radial direction were similarly formed was obtained.

Claims (4)

A solubilized collagen fiber having an ash content of 5% by mass or less obtained by spinning an aqueous solution of solubilized collagen having an isoionic point of pH 5.0 or less in isopropyl alcohol measured by an ash content measurement method according to JISK6503: 2001 In a sheet by wet papermaking, it is dried by air-drying or vacuum distillation, and a small amount of collagen remaining on the fiber surface is re-dissolved by the trace amount of water remaining after the isopropyl alcohol has evaporated, and the sheet is in this state. The solubilized collagen fiber sheet is characterized in that the re-dissolved collagen is solidified by drying and the fibers are bonded together by collagen, and the basis weight is 5 to 50 g / m ² . Measured by atomic absorption spectrophotometry with an ash content of 5% by mass or less obtained by spinning an aqueous solution of solubilized collagen having an isoionic point of pH 5.0 or less in isopropyl alcohol by an ash content measurement method according to JISK6503: 2001. A solubilized collagen fiber having a Na content of 2% by mass or less is squeezed into a sheet by a wet papermaking method in isopropyl alcohol, and then dried by an air drying method or a vacuum distillation method. A small amount of collagen on the fiber surface is re-dissolved by moisture, and the re-dissolved collagen is solidified by drying the sheet in this state, the fibers are bonded by collagen, and the basis weight is 5 to 50 g / m ^2. Characterized solubilized collagen fiber sheet.
The solubilized collagen fiber sheet according to claim 1 or 2, wherein the solubilized collagen fiber sheet is a non-woven fabric made of short solubilized collagen fibers having a fiber length of 0.5 to 20 mm. A pack cosmetic comprising a laminate obtained by laminating the solubilized collagen fiber sheet according to claim 1 or 2 and a moisture shielding sheet which is a 0.01 to 2 mm soft plastic film having water passage holes.