JP2007197649A - Sponge made of polysaccharide - Google Patents

Abstract

[Problem] To provide a sponge made of a natural substance having excellent quality and low manufacturing cost.
SOLUTION: A manufacturing method has already been established, and for the production of general-purpose products, a cheaply manufactured polysaccharide viscose solution, copper ammonia solution or the like is used, and a water-soluble polymer is added thereto, After solidifying, it is obtained by hydrothermal treatment and further freeze-drying. Examples of the polysaccharide substance include cellulose or a derivative thereof, chitin or deacetylated chitin or a derivative thereof, a mixture of cellulose and chitin, or a mixture of cellulose and deacetylated chitin. It is possible to obtain a high-quality polysaccharide sponge having a high-quality performance from a polysaccharide substance by a simple method and at a low production cost.
[Selection figure] None

Description

Detailed Description of the Invention

The present invention mainly includes cosmetics such as face masks, protective materials after depilation, menstrual tampons, diapers, incontinence pads, anti-adhesion agents, wound protective agents, deodorant filters, allergy removal filters and masks, and virus removal filters. It is widely used for industrial materials such as masks, and is inexpensive and highly porous. The pore has a uniform structure on the surface and inner layer, so it is hydrophilic, has a high water absorption rate, and has a high water absorption rate. The present invention relates to a sponge containing a chemical substance or a drug as a second component in addition to a sponge composed of a porous material having high strength and high air permeability and a polysaccharide substance.

The polysaccharide substance is usually a polymer and has been used in the form of fibers and the like, and is a highly safe substance. Also, since it is a natural substance, it has excellent hydrophilicity and has little irritation to living bodies such as skin, so it is widely used in cosmetics and medical fields. It is the same as other natural substances such as collagen materials. Are preferably used.

As the molded body, the shape of the porous sponge is limited to natural materials, and there are strong demands from various fields for polysaccharide substances, and many studies have been made heretofore. Many of them have drawbacks such as high production cost and insufficient performance, and there have been almost no successful examples in the cosmetics, medical field and industrial field regarding their practical application.

Among the polysaccharide substances, cellulose, chitin, deacetylated chitin, sodium alginate, etc. are common as general-purpose substances. As a past example regarding the production of these sponges, there is a method in which mirabilite is added to a rayon viscose solution, solidified, further subjected to hot water treatment and then dried. In this case, sodium sulfate has a disadvantage that the rayon viscose solution is solidified earlier and the solution is solidified during the process. As a countermeasure, Japanese Patent Application Laid-Open No. 9-278925 (viscose sponge and its production method; applicant: Daiwabo Rayon Co., Ltd.) and the like use a method of using viscose having a low maturity (Salt Test value) in order to delay solidification. Proposed. However, although what is obtained from such a method is a porous body, the final product has hard physical properties in a dry state, and does not retain the unique softness of sponge before absorbing water. Therefore, it is practically used only for daily necessities such as scourers and has a limit as a product.

An example of a method for producing a sponge of deacetylated chitin (chitosan) is disclosed in Japanese Patent Application Laid-Open No. 2003-292501 (chitosan sponge and its production method; applicant, Koyo Chemical Co., Ltd.). In this method, since chitosan is dissolved in acetic acid, the acetic acid solution is directly frozen and lyophilized. That is, water and acetic acid are removed at the drying stage, and pores are formed, but acetic acid cannot be completely removed, and a small amount of acetic acid remains in the final sponge, so it retains an acetic acid odor, It is almost impossible to use for medical products, cosmetics, etc., and the manufacturing process is complicated, resulting in high manufacturing costs.

JP-A-9-278925 JP2003-292501

Therefore, in the conventional method, it has been very difficult to obtain a sponge made of polysaccharides such as cellulose, chitin, chitosan, etc. at low cost, with good performance, particularly high water absorption, and flexibility. Moreover, it could not be widely used for medical products and cosmetics. Also, the manufacturing method is complicated and the manufacturing cost is high. An object of the present invention is to solve such a problem.

As a result of diligent efforts to solve these problems, the inventors have found a method for producing a sponge made of a polysaccharide substance that is inexpensive, flexible, highly water-absorbing, and highly safe. That is, when producing a sponge composed of polysaccharides, a water-soluble polymer is mixed with a viscose solution of a polysaccharide, a copper ammonium solution, and an N-MMO solution, solidified, then hydrothermally treated, and further freeze-dried. This is a method for producing a sponge.

Low cost and high performance for cosmetics, purifier filters, air-conditioning filters, virus protection masks and filters, allergen protection masks and filters, etc. due to the hydrophilicity of polysaccharides, the breathability of sponges, and the addition of the second component Can offer.

Embodiments of the present invention will be described below.
The polysaccharide of the present invention refers to a polysaccharide usually separated from natural substances. For example, it refers to cellulose and its derivatives that are pulp or cotton linters separated from wood, kenaf, bamboo, etc., and chitosan and its derivatives that are separated from crustacean exoskeletons such as shrimp. Here, chitosan refers to deacetylated chitin that has been deacetylated by treating chitin with an aqueous caustic soda solution at a high temperature and high concentration.

The viscose solution is generally prepared by a method called the xanthate method. In other words, cellulose such as pulp is immersed in an aqueous caustic soda solution to make alkali cellulose, pressed, ground, aged and then added with carbon disulfide to make cellulose xanthate, then dissolved in caustic soda and aged to give a viscose solution Say.

As for chitin, viscose can be prepared by the same method as cellulose. A method for producing a chitin viscose solution can be produced by a method for producing chitin viscose described in JP-A-9-241828 (manufacturing method of chitin chitosan fiber and structure; Omikenshi Co., Ltd.). However, since chitin is dissolved in water as it is after preparing alkali chitin which can be produced in the process of preparing viscose, this solution can be used in the present invention in the same manner as the viscose solution.

In the present invention, a polysaccharide such as cellulose needs to be in an aqueous solution state, and if it is in this state, the production conditions of the aqueous solution are not particularly problematic. As a production condition, a viscose solution production method used when producing rayon fiber obtained from wood pulp is common. The concentration of cellulose used in the present invention is preferably 0.5 to 8% by weight, more preferably 1 to 3% by weight. Generally, the concentration of the viscose liquid used for the production of rayon fiber is about 5 to 10% by weight. When this is used, it is diluted with water or an alkaline aqueous solution to a necessary concentration. Of course, a viscose having a concentration actually used may be prepared.

In general, the copper ammonia solution is prepared by dissolving cotton linter in copper hydroxide tetramine prepared by adding an aqueous ammonia solution to copper hydroxide. As the organic solvent solution, a solution composed of an organic solvent N-methylmorpholine N-oxide (N-MMO) used in general commercially available regenerated cellulose is used. N-MMO hydrate is melted at 90 ° C. to make a transparent liquid, defoamed, and then pulp is added. After swelling, a viscous and transparent liquid is obtained after about 2 hours. Adjust to about 8% by weight.

The water-soluble polymer of the present invention refers to a polymer that is soluble in water, particularly preferably a polymer that is insoluble in cold water and soluble in hot water, polyvinyl alcohol, polyvinyl pyrrolidone, etc. are preferred, and polyvinyl alcohol is further Preferably used.

Among them, the water-soluble polyvinyl alcohol preferably has a saponification degree of 90 or more, more preferably 98 or more. The particle size is preferably from 20 mesh under to 200 mesh under, more preferably from 30 mesh under to 100 mesh under. The viscosity is 20 ° C. and a 4% aqueous solution, preferably 5 to 50 mPa · s, more preferably 10 to 40 Pa · s.

The amount of addition is preferably 10 to 60% by weight (water-soluble polymer weight × 100 / viscose solution weight + water-soluble polymer weight), more preferably 25 to 40% by weight with respect to the viscose solution and the like. is there. The mixing of the viscose solution and the water-soluble polymer is preferably uniform, but can be sufficiently performed by a general mixing method, and can be industrially performed by a general kneader such as a kneader. When the fluidity of the mixture is poor, polyethylene glycol or ethylene glycol may be added to improve moldability. Since this mixture is not usually suspicious by simple mixing, it is necessary to leave it for a long time after the mixing is completed, or to coagulate it according to the shape of the sponge to be prepared by a method such as heat treatment.

For example, when producing a sheet, the mixture can be filled and solidified as a sheet using a tray having a certain depth. In the case of heat treatment, the treatment is preferably performed at a temperature of 80 ° C. or higher. In particular, the treatment may be performed at a boiling steam temperature. In the case of leaving, it is preferably 24 hours or longer. Those that have been solidified are treated with hot water. The hot water treatment is performed for the purpose of completely removing water-soluble substances in the solidified body, and may be a general method, preferably at 80 ° C. or higher or with boiling water, and at about 120 ° C. in an autoclave. You can also The treatment time is shorter as the treatment temperature is higher, but the treatment for 1 hour or more is preferable for boiling water, the treatment for 10 minutes or more is preferred for the autoclave, and the water-soluble substance in the mixture needs to be completely removed. However, the end of the treatment can be judged by analyzing substances that are normally released into water, such as water-soluble polymers, and confirming the disappearance.

At the time when the hydrothermal treatment is completed, the present invention is created as a gel material in which the porous body sufficiently contains water. This gel-like substance is dried by a normal freeze vacuum drying method. As the freeze-drying conditions, usual methods used in food production can be adopted. For example, after sufficient water is contained in the gel material, the gel material is sufficiently frozen at a temperature of −40 ° C. to −15 ° C., and then the atmosphere temperature is 10 ° C. It is common to carry out at 50 ° C. Although the time varies depending on the thickness of the shape to be lyophilized, the thickness of about 1 to 3 mm can be completed in about 10 to 24 hours even if about 5 sheets are stacked. Thicker ones require a longer time. However, the vacuum freeze-drying condition is not particularly important in the present invention, and it is possible to produce a good quality under a wide range of conditions. The end is a state in which water is almost removed, and a state in which there is no change in the degree of vacuum is a standard. After freeze-drying, it can be taken out as a porous sponge.

The shape can be obtained in any shape such as a sheet shape, a block shape, and a cylindrical shape by using a mold. In the case of a sheet shape, the thickness is generally 0.5 mm to 2 mm. However, in addition to directly forming the thickness, first, a thickness of about 10 cm may be freeze-dried, sliced after drying, and formed into a thin sheet. The sponge obtained is a porous body with a pore size of about 20 to 200 μφ and a specific gravity of 0.01 to 0.1 g / cm ³ . Also, the water absorption speed is 3 seconds or less (5 cm × 5 cm piece of the sample of the present invention is immersed in water and the entire sample absorbs water), the water absorption ratio is 25 times or more, and the water absorption characteristics are high. .

The present invention is characterized in that a sufficient amount of other chemical substances or drugs can be added to the sponge. That is, a water-insoluble substance can be added at the stage of mixing the viscose liquid, and a water-soluble substance can be added after being dissolved or dispersed in water at the stage of a gel substance and frozen. It can be dried. Both can ultimately be retained in the sponge as it was added after lyophilization. During the process, since the method of applying temperature is small, even a substance having poor heat resistance does not lose its activity.

In the present invention, any chemical substance and drug can be added. For example, biological components such as collagen, gelatin, hyaluronic acid, chondroitin, vitamins, various adsorbents such as activated carbon, silica, diatomaceous earth, zeolite, It is possible to add starch, cyclodextrin, phthalocyanine, titanium oxide metal, cellulose copper salt, calcium phosphate, catechin, apatite, fragrance, adsorbent, fungicide, insecticide, etc., but not limited to these, Anything can be added. Therefore, by adding the chemicals and the characteristics of the drug, the characteristics of the sponge can be further enhanced. That is, this enables the sponge of the present invention to retain functions such as deodorizing properties, virus supplementing properties, allergen supplementing properties, antibacterial properties, fungicidal properties, and various adsorptive properties.

As described above, since the production method of the present invention consists of very simple steps, the production cost is particularly low, and the resulting sponge also has high performance. Unnecessary substances in the process are treated with hydrothermal treatment. The impurities are not left and the safety is high. In addition, the water absorption characteristics of the sponge are also high, and it is possible to make a sponge having various characteristics by including chemical substances, drugs, and the like.
Hereinafter, the contents of the present invention will be described in detail by way of examples.

Wood pulp was immersed in a 17.5% by weight aqueous caustic soda solution to produce alkali cellulose. After pressing, grinding and aging, 35% by weight of carbon disulfide was added to cellulose to obtain cellulose xanthate. This cellulose xanthate was dissolved in a 35% by weight aqueous caustic soda solution. Viscose had a cellulose concentration of 8.9% and an alkali concentration of 6%. This was aged at 20 ° C. for 24 hours, and the resulting viscose solution was used for the production of a cellulose sponge.

Viscose was diluted with water to 2 wt%. A powder of polyvinyl alcohol (PVA; trade name VS20, 80 mesh under, manufactured by Nippon Vinegar Poval Co., Ltd.) was added and mixed at a ratio of viscose: PVA = 2: 1. After thoroughly mixing this with a kneader, the mixture was filled into a container having a length of 25 cm, a width of 30 cm, and a depth of 2 mm. Further, the filled mixture was heat-treated at 100 ° C. for 1 hour to solidify and then immersed in boiling water to sufficiently remove water-soluble substances. The product was a translucent gel-like porous material sufficiently containing water.

In a state where water was contained in this gel substance, it was frozen at −30 ° C. for 2 hours and subjected to freeze-drying. Freezing and vacuum drying conditions were carried out at a vacuum degree of 4 Pa and an atmospheric temperature of 30 ° C. for 18 hours. As a result, a white sheet having a length of 24 cm, a width of 28 cm, and a thickness of 2 mm was obtained. The density of the sheet is 0.025 g / cm ³ , and when a small piece of 5 cm × 5 cm is put into water placed in a wide container, the time required for water to enter the entire sheet is 1 second or less. The water absorption speed was very fast. Further, after 10 cm × 10 cm is sufficiently immersed in water, it is taken out from the water, suspended in the air until no more water is dropped, the weight (A) is measured, and the sheet weight (B) before immersion is taken as the water absorption ratio = When AB / B was calculated, it was 42 times, indicating high water absorption.

When this sheet was used for a face mask, it had good skin adhesion, water retention and flexibility, and was very well received by users.

Alkaline chitin was prepared by adding 42% caustic soda to 80 mesh chitin powder (dissolved in a 9: 1 solution of dimethylacetamide and lithium chloride and having a measured molecular weight of about 1 million). Furthermore, after pressing, crushing, and aging, 30% by weight of carbon disulfide was added to form chitin xanthate, and ice was added to this to melt to prepare chitin viscose. Further, it was diluted with water to a concentration of 1.5% by weight, and used as a raw material for creating sponges.

Polyvinyl alcohol (VC10 manufactured by Nihon Vinegar Bipovar Co., Ltd .; Ken excessive 99%, viscosity 11 mPas, particle size 30 mesh under) is added at a ratio of 2: 1 to 1.5% by weight of chitin viscose, and kneaded and mixed thoroughly. did. The obtained paste-like substance was filled in a tray container having a length of 30 cm, a width of 40 cm, and a thickness of 3 mm, and heat-treated at 100 ° C. for 2 hours for solidification. Further, it was immersed in water and treated in an autoclave at 120 ° C. for 40 minutes. When washed thoroughly with water, a translucent gel-like substance was obtained.

The gel material was frozen at −30 ° C. and freeze-dried. When the degree of vacuum was 12 Pa and the ambient temperature was 40 ° C. for 24 hours, white chitin (deacetylation degree 60%) sponge was obtained. The density was 0.019 and it had high porosity.

  This sponge was cut into a width of 3 cm and a length of 20 cm, sterilized, and left as a paranasal sinus protective agent after nasal septal correction for 7 days. When removed, the removal was very smooth and bleeding from the wound surface It was very useful as an anti-adhesion agent.

A solution in which the cellulose viscose used in Example 1 and the chitin viscose used in Example 2 are mixed, the weight ratio of cellulose to chitin is 7: 3, and the solid weight in the mixed solution is 2% by weight. Got. Furthermore, 30% by weight of polyvinyl alcohol (Poval VC10, manufactured by Nihon Vinegar Bipoval Co., Ltd .; viscosity 10, saponification degree 99.3, particle size 30 mesh pass) was mixed with this solution to obtain a paste. This was introduced into a molding machine having a thickness of 1.5 mm, thermally coagulated at 100 ° C. for 1 hour, and treated with boiling water for 2 hours. The obtained gel-like substance was sufficiently removed with impurities, and after sufficiently containing a 3% aqueous solution of polyethylene glycol 600, it was frozen at -30 ° C. After confirmation of freezing, lyophilization was performed. Freeze-drying was performed at 30 ° C. for 18 hours to obtain a white sponge sheet having a thickness of 1.7 mm.

The water absorption speed was 1 second or less, and the water absorption magnification was 37 times. This was used as an incontinence pad absorbent body, sandwiched between a water-permeable topsheet and a water-permeable backsheet, and attached to an incontinence patient. As a result, the absorbent body adsorbed urine and odor, and was successfully used as an incontinence pad.

The cellulose viscose solution used in Example 1 was used. Viscose was diluted with water to 3 wt%. To this solution, 40% by weight of polyvinyl alcohol powder (Nippon Vinegar Poval Co., Ltd., JF-17; viscosity 32 Pa · s, particle size 30 mesh pass, Ken excessive 99%) (solution: polyvinyl alcohol = 3: 2) was added, and further 30% by weight of artificial zeolite (manufactured by Chubu Electric Power Co., Inc.) was added and mixed thoroughly, and then filled into a 3 mm thick container. It was heated and coagulated in contact with water vapor. Further, it was treated with hot water for 3 hours.

The resulting gel-like substance was thoroughly washed with water, and the gel body was sufficiently filled with water, and then subjected to lyophilization. The freeze-drying was performed for 20 hours under a 20 Pas vacuum at a shelf temperature of 30 ° C. after freezing the gel material at −30 ° C.

The completed product was in the form of a sheet in which artificial zeolite was dispersed in cellulose sponge. Using this sheet, the amount of adsorption of ammonia, hydrogen sulfide, acetaldehyde, acetic acid, and trimethylamine, which are malodorous components, was measured according to the Japan Chemical Fibers Association and unified test method. showed that. In the treatment, a 10 cm × 10 cm sheet was put into a container containing gas, and the gas concentration after 24 hours was measured after 2 hours (Table 1).

Claims (5)

From a polysaccharide substance produced by mixing a water-soluble polymer with a viscose solution or a copper ammonium solution of a polysaccharide substance, or an organic solvent solution, coagulating, hydrothermal treatment, and freeze-drying Sponge. The sponge according to claim 1, wherein the polysaccharide substance is cellulose or a derivative thereof. The sponge according to claim 1, wherein the polysaccharide substance is chitin, deacetylated chitin or a derivative thereof. The sponge according to claim 1, wherein the polysaccharide substance is a mixture of cellulose and chitin or a mixture of cellulose and deacetylated chitin. 2. The sponge according to claim 1, which contains a chemical substance or a drug as a second component in addition to the polysaccharide substance.