JPH0967459A - Porous film or sheet - Google Patents

Abstract

(57) Abstract: A porous film or sheet excellent in water vapor permeability is provided. Kind Code: A1 A synthetic polypeptide, an organic solvent that dissolves the synthetic polypeptide, a volatile organic solvent that is compatible with the organic solvent that dissolves the synthetic polypeptide, and a mixture of water and water are cast to form a film. The resulting porous film or sheet.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a porous film or sheet which is useful as a wound dressing material, an outer layer material for diapers, a material for clothes, etc., which requires air permeability.

[0002]

2. Description of the Related Art For the purpose of protecting the affected area for treating wounds
Wound dressing materials, outer layer materials such as diapers, sports equipment materials, etc.
Has a breathability that allows water vapor to pass through but water droplets to pass through
The film or sheet or the like has is used. This
As the film or sheet, the inorganic filler is added.
After molding the synthetic resin into a film, stretch it to make a fine slip.
A film that has been formed into
Chemicals, Vol. 15, No. 10, published by Technomart (19
91), Separation / Transportation Functional Materials, edited by Japan Society of Polymer Science, Kyoritsu Publishing
Published (1991), Japanese Patent Publication No. 56-45773, Japanese Patent Publication
56-17216]. In addition, poly-γ-methyl-
Medical film based on L-glutamate (Japanese Patent Publication No. 51-
No. 42878) and a wound covering using a silicone film as a base material.
Cover material [Science,215174
-176 (1982)] is also known. The poly-γ-
Water vapor transmission of methyl-L-glutamate film and silicone film
Excessive is about 1,000 (g / m at 20 μm thickness) ²/Day)
It is.

Further, the polyurethane membrane used as a wound dressing has a water vapor permeability of 450 to 850 (g).
/ M ² / day), even for segmented polyurethane membranes with the highest water vapor transmission rate, the value is 4,300 at a thickness of 30 μm.
It is known to be (g / m ² / day) [Nigata Journal, 10 , 165-180 (1990)].

[0004]

An object of the present invention is to provide a porous polypeptide film or sheet having excellent water vapor permeability.

[0005]

The present invention provides a synthetic polypeptide, an organic solvent that dissolves the synthetic polypeptide, a volatile organic solvent that is compatible with the organic solvent that dissolves the synthetic polypeptide, and water, and water. Provided is a porous film or sheet obtained by casting a mixed solution. Further, the present invention is a casting film formation of a mixed solution of a synthetic polypeptide, an organic solvent that dissolves the synthetic polypeptide, a volatile organic solvent that is compatible with the organic solvent that dissolves the synthetic polypeptide and is miscible with water, and water. A method of making a porous film or sheet is also provided.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Although any synthetic polypeptide can be used in the present invention, a synthetic polypeptide capable of forming α-helix is preferable. Examples of synthetic polypeptides capable of forming α-helix include polyglutamic acid derivatives such as poly-γ-methyl-L-glutamate, poly-γ-ethyl-L-glutamate, poly-γ-benzyl-L-glutamate, and poly-glutamate. Examples thereof include polyaspartic acid derivatives such as β-benzyl-L-aspartate, poly-L-leucine, poly-L-alanine and the like. As these synthetic polypeptides, commercially available products or those produced according to the method described in the literature can be used as they are or after diluted with a solvent. Examples of commercially available synthetic polypeptides capable of forming α-helix include Ajiquat A-20.
00, XB-900 [Ajinomoto Co., Inc.], PLG-10,
-20, -30 [Kyowa Hakko Kogyo Co., Ltd.] and other poly-γ-
Methyl-L-glutamate may be mentioned.

As the organic solvent for dissolving the synthetic polypeptide, a poorly water-soluble helix solvent may be used, and examples thereof include halogenated hydrocarbon solvents such as 1,2-dichloroethane, dichloromethane, chloroform and tetrachloroethane, benzene and the like. Examples include aromatic solvents. These solvents can be used alone or as a mixture. Examples of the volatile organic solvent that dissolves the synthetic polypeptide and is miscible with water include lower alcohols having up to 3 carbon atoms, acetone, methyl ethyl ketone and tetrahydrofuran. Among the organic solvents, alcohols such as methyl alcohol, ethyl alcohol, n-propanol and iso-propanol are more preferable, and ethyl alcohol is particularly preferable. These solvents can be used alone or as a mixture.

As the water, tap water can be used, but ion-exchanged water is preferably used. The mixing ratio of the synthetic polypeptide, the organic solvent that dissolves the synthetic polypeptide, the volatile organic solvent that is compatible with the organic solvent that dissolves the synthetic polypeptide, and that is miscible with water, and the water is
5% by weight, organic solvent capable of dissolving synthetic polypeptide 45 to
49% by weight, a volatile organic solvent compatible with an organic solvent capable of dissolving a synthetic polypeptide and miscible with water 17.5 to 47.
It is preferably a mixed liquid of 5% by weight and 2.5 to 32.5% by weight of water.

Further, in preparing the mixed solution, a synthetic polypeptide solution comprising a synthetic polypeptide and an organic solvent dissolving the synthetic polypeptide, and a volatilization compatible with the organic solvent dissolving the synthetic polypeptide and miscible with water. It is preferable to separately prepare an aqueous solution of the organic solvent and water, and then mix them. The synthetic polypeptide concentration of the synthetic polypeptide solution consisting of the synthetic polypeptide and an organic solvent capable of dissolving the synthetic polypeptide is appropriately determined in consideration of the type of the synthetic polypeptide, the molecular weight, the film-forming conditions, and the concentration of the synthetic polypeptide after mixing. You can use it after increasing or decreasing it,
2 to 10% by weight of synthetic polypeptide, preferably 3 to 8
%, Particularly preferably 3 to 5% by weight is used. In the case where the synthetic polypeptide is poly-γ-methyl-L-glutamate obtained by polymerization in a helix solvent, it may be difficult to redissolve it when it is taken out as a solid. The solution thus obtained may be used as it is, or after being concentrated or diluted with the solvent.

An aqueous solution consisting of water and a volatile organic solvent which is compatible with an organic solvent which dissolves the synthetic polypeptide and which is miscible with water, contains 5 to 65% by weight, preferably 10 to 60% by weight of water. To use. In preparing the mixed solution, 30 parts by weight of a synthetic polypeptide solution consisting of a synthetic polypeptide and an organic solvent dissolving the synthetic polypeptide and a volatile organic solvent compatible with the organic solvent dissolving the synthetic polypeptide and miscible with water. Aqueous solution consisting of solvent and water
It is preferred to mix parts by weight.

When the mixed solution is prepared, the synthetic polypeptide may be precipitated and may become cloudy depending on the addition ratio. In this case, cloudiness of the mixed solution can be prevented by increasing the solution temperature and the solubility of the synthetic polypeptide. The temperature varies depending on the solvent used, but is, for example, 35 to 60 ° C.
Is preferred. If necessary, an antibacterial agent,
It may also contain organic or inorganic fillers, pigments, dyes and the like.

The casting film formation is a film formation method in which the mixed solution is cast in a mold or on a flat plate such as a glass plate and then the solvent is allowed to escape to solidify to form a film or sheet. In order to prepare a large amount of the same film in a short time, the method using a casting knife is practical and preferable. An example of the method for producing the porous film or sheet of the present invention is shown below. Pour a mixture of synthetic polypeptide, an organic solvent that dissolves the synthetic polypeptide, a volatile organic solvent that is compatible with the organic solvent that dissolves the synthetic polypeptide and is miscible with water, and water into a flat plate such as a petri dish and leave it for a while. The porous film or sheet can be produced by allowing the solvent to escape.

In the case of industrially forming a film, the mixed solution can be formed into a film by using, for example, a doctor blade, and a porous film or sheet can be produced. As a method for escaping the solvent, the mixed solution may be cast on a flat plate such as a petri dish and allowed to stand at room temperature to allow the solvent to escape.However, after pouring the mixed solution on the flat plate, the flat plate is rapidly cooled from the surroundings. Liquid temperature is 0 to 25 ° C, preferably 0 to
A method of keeping at 15 ° C. and making a non-flowing gel state to allow the solvent to escape, or 25 to 60 ° C., preferably 25 to 40
A method of escaping the solvent in a fluid state at a temperature of ° C may be used. The atmosphere in which the solvent is allowed to escape may be a normal working environment, but it is preferably performed in a nitrogen gas atmosphere in order to reduce changes in environmental conditions. The rate of solvent escape depends on the type of solvent, concentration, temperature, and other conditions. After the film or sheet is formed, if necessary, 80 to 13
The solvent can be more completely removed by a method of heat treatment at 0 ° C., preferably 100 to 120 ° C. for 1 to 3 hours, or a method of leaving it under vacuum for 1 to 2 days.

The film thickness of the film or sheet can be adjusted by, for example, the concentration of the synthetic polypeptide in the mixed solution used for casting film formation or the amount of the solution to be cast. The film thickness is not particularly limited, but is preferably 1 to 500 μm, more preferably 3 to 150 μm. Particularly, as a wound dressing material, 20 to 80
μm is highly preferred. In the present invention, the film thickness is 200
A film having a thickness of 200 μm or less is called a film and a film having a thickness of more than 200 μm is called a sheet.

The porosity which affects the water vapor permeability can be adjusted by adjusting, for example, the concentration of synthetic polypeptide or the concentration of water. Water vapor permeability is 4,000
It is 0 to 10,000 (g / m ² / day). A known film or sheet obtained by casting a solution containing only a synthetic polypeptide and an organic solvent capable of dissolving the synthetic polypeptide is non-porous. On the other hand, the film or sheet obtained by the present invention is porous with distorted cavities having a diameter of about 0.1 to 100 μm. Moreover, the adjacent cavities in the film or sheet may be partially continuous, but have an independent structure partitioned by an ultrathin film, and the front and back surfaces form an integral skin layer, and the front and back surfaces are formed. Is in a sealed state.

The water vapor permeability of a polymer film or sheet depends on the film thickness, and the thinner the film, the greater the permeability. In addition, synthetic polypeptides are known to have excellent water vapor permeability due to their molecular structure. Therefore, the porous film or sheet of the present invention is porous and has an extremely thin cell thickness, so that the water vapor permeability thereof is significantly improved as compared with the conventionally known ones. In addition, since the cross section of the membrane is independent and porous and the front and back sides are covered with the skin layer, it is suitable as a wound dressing capable of preventing the invasion of bacteria.

The skin has both a respiratory function such as skin respiration and water vapor transmission and a barrier function such as prevention of invasion of bacteria and retention of body fluid, and it is preferable that the wound covering material to be applied to an affected area such as a burn has both of these functions. The amount of water disperse on the skin is about 4,300 g / m ² / m in II degree burn wounds.
Day, about from granulating wound 5,100 g / m ² / day, it is said that from Tokawa wounds than about 3,600g / m ² / day.
Therefore, the water vapor permeability of the wound dressing is preferably higher than this. The porous film of the present invention satisfies this condition and is particularly useful as a wound dressing material.

Further, the porous film or sheet of the present invention has excellent water vapor permeability as compared with a known cast film obtained by a conventional method, has a high gas permeability, and is particularly excellent in carbon dioxide selective permeability.

[0019]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the following examples. Physical properties shown in Examples and Comparative Examples were measured or observed by the following methods.

(1) Water vapor transmission rate Water vapor transmission rate tester (L80-4000 type, Switzerland
Dr. LYSSY), measurement temperature 40 ℃, relative humidity 90%, 19μm PET as a standard sample
It measured using the film (25 g / m < ² > / day) and using a 10-well holder.

(2) Gas permeability gas permeability tester (GPM-500 type, Swiss D
r. (Manufactured by LYSSY) was used, and a mixed gas of oxygen, nitrogen and carbon dioxide (DRY gas) was used as a test gas, and measurement was performed in accordance with Japanese Industrial Standards (JIS) K7129 (1992).

(3) Film observation Using a scanning electron microscope (S-510 type, manufactured by Hitachi),
The fracture surface and the front and back surfaces of the film were observed.

Example 1 "PLG-20" [1,2-dichloroethane solvent, poly-γ-methyl-L-glutamate (molecular weight 88,000)
0) 8% by weight solution, manufactured by Kyowa Hakko Kogyo Co., Ltd.]
30 g of a solution diluted to 3% by weight with dichloroethane was taken in a 100 ml glass beaker. While stirring with a magnetic stirrer, 24 g of a mixed solution of 10 parts by weight of ion-exchanged water and 90 parts by weight of ethanol was slowly added and sufficiently stirred and mixed, and then a part of the mixed solution was 100 m.
It was poured into an m-diameter flat petri dish, the petri dish was rapidly cooled from the surroundings, and the liquid temperature was lowered to 15 ° C or lower to give a gel state. afterwards,
The solvent was allowed to escape under a nitrogen gas atmosphere at 17 ° C. or less to obtain a marshmallow-like porous film 1.

When the porous film 1 was observed with a scanning electron microscope, the film had a thickness of about 167 μm and distorted cavities with a diameter of several μm to several tens of μm were formed.
Each cavity was a partially continuous but independent structure separated by an ultra-thin film. In addition, the front and back surfaces of the film were covered with a thin skin layer, and thus it was confirmed that the film was a sealed porous film. The water vapor permeability of the porous film was 6,100 g / m ² / day.

Example 2 "PLG-15" [1,2-dichloroethane solvent, poly-γ-methyl-L-glutamate (molecular weight 29,70
0) 10% by weight solution, manufactured by Kyowa Hakko Kogyo Co., Ltd.]
After 30 g of a mixed solution of 10 parts by weight of ion-exchanged water and 90 parts by weight of ethanol was sufficiently stirred and mixed with 30 g of a solution diluted with 2-dichloroethane to 3% by weight, a part of the mixed solution was used in Example 1 A marshmallow-like porous film 2 was obtained by the same method as described above.

When the porous film 2 was observed with a scanning electron microscope, it was confirmed that it had a thickness of 175 μm and was the same sealed porous film as the film 1. The water vapor permeability of the porous film 2 is 6,200 g.
/ M ² / day.

Example 3 30 g of a solution prepared by diluting "PLG-20" used in Example 1 with 1,2-dichloroethane to 3% by weight, a mixed solution of 10 parts by weight of ion-exchanged water and 90 parts by weight of ethanol. After sufficiently stirring and mixing 28 g, a marshmallow-like porous film 3 was obtained by the same method as in Example 1 using a part of the mixed solution.

When the porous film 3 was observed with a scanning electron microscope, it was confirmed that the porous film 3 had a thickness of 70 μm and was a closed porous film like the film 1. The water vapor permeability of the porous film 3 is 6,500.
It was g / m ² / day.

Example 4 "PBzLG" [poly-γ-benzyl-L-glutamate (molecular weight 23,000), manufactured by Kyowa Hakko Kogyo Co., Ltd.] diluted with chloroform to a concentration of 5% by weight 30
After thoroughly stirring and mixing 30 g of a mixed solution of 10 parts by weight of ion-exchanged water and 90 parts by weight of ethanol with g, a part of the mixed solution was used to form the marshmallow-like porous film 4 in the same manner as in Example 1. Obtained.

When the porous film 4 was observed with a scanning electron microscope, it was confirmed that the film had a thickness of 67 μm and was the same sealed porous film as the film 1. The water vapor permeability of the porous film 4 is 6,000 g /
It was m ² / day.

Example 5 30 g of a solution prepared by diluting "PLG-20" used in Example 1 with 1,2-dichloroethane to 3% by weight was used.
Collected in a 00 ml glass beaker. While stirring with a magnetic stirrer, slowly add 28 g of a mixed solution of 10 parts by weight of ion-exchanged water and 90 parts by weight of ethanol, thoroughly stir and mix, and then part of the mixed solution is placed on a glass plate fixed on a horizontal table. The solution was cast and the solvent was allowed to escape under a nitrogen gas atmosphere at 28 ° C. to obtain a porous film 5.

When the porous film 5 was observed with a scanning electron microscope, the film thickness was about 19.1 μm.
Distorted cavities with a diameter of several μm were formed. Each cavity is
Although it was partially continuous, it had an independent structure partitioned by an ultrathin film. In addition, the front and back surfaces of the film were covered with a thin skin layer, and thus it was confirmed that the film was a sealed porous film. The water vapor permeability of the porous film 5 was 8,000 g / m ² / day.

Example 6 30 g of a solution prepared by diluting "PLG-15" used in Example 2 with 1,2-dichloroethane to 3% by weight was mixed with 10 parts by weight of ion-exchanged water and 90 parts by weight of ethanol. After sufficiently stirring and mixing 26 g, a part of the mixed liquid was used to obtain a marshmallow-like porous film 6 by the same method as in Example 5.

When the porous film 6 was observed with a scanning electron microscope, it was confirmed that it had a thickness of 26.3 μm and was a closed porous film similar to the film 5.
The water vapor permeability of the porous film 6 is 7,40.
It was 0 g / m ² / day.

Example 7 30 g of a solution prepared by diluting "PLG-20" used in Example 1 with 1,2-dichloroethane to 3% by weight was added.
Collected in a 00 ml glass beaker. While stirring with a magnetic stirrer, slowly add 28 g of a mixed solution of 10 parts by weight of ion-exchanged water and 90 parts by weight of ethanol, thoroughly stir and mix, and then part of the mixed solution is placed on a glass plate fixed on a horizontal table. The solution was cast and the solvent was allowed to escape under a nitrogen gas atmosphere at 28 ° C. to obtain a porous film 7.

When the porous film 7 was observed with a scanning electron microscope, it was confirmed that the porous film 7 had a thickness of 10.5 μm and was a closed porous film like the film 5.
The water vapor permeability of the porous film 7 is 9,700.
It was g / m ² / day.

Example 8 30 g of a solution prepared by diluting "PLG-20" used in Example 1 with 1,2-dichloroethane to 3% by weight was added.
Collected in a 00 ml glass beaker. While stirring with a magnetic stirrer, slowly add 28 g of a mixed solution of 10 parts by weight of ion-exchanged water and 90 parts by weight of ethanol, thoroughly stir and mix, and then part of the mixed solution is placed on a glass plate fixed on a horizontal table. The solution was cast and the solvent was allowed to escape under a nitrogen gas atmosphere at 28 ° C. to obtain a porous film 8.

When the porous film 8 was observed with a scanning electron microscope, it was confirmed that the porous film 8 had a thickness of 57.8 μm and was sealed like the film 5.
In addition, as a result of measuring the gas permeability of the porous film 8, any of oxygen, nitrogen, and carbon dioxide gas was measured by a permeability tester (10,000 ml / m ² / day for oxygen,
It exceeded tens of thousands of ml / m ² / day for nitrogen and carbon dioxide.

Comparative Example 1 30 g of the 3% solution of "PLG-20" used in Example 1 was poured into a flat petri dish, the solvent was allowed to escape under a nitrogen gas atmosphere at room temperature, and the film thickness was 21 μm and was semitransparent. A cast film a was obtained. The cast film a had no cavities in its cross section, and the front and back surfaces were smooth. The water vapor permeability of the cast film a was 2,600 g / m ² / day.

Comparative Example 2 The 3% solution of "PLG-20" used in Example 1 was poured into a flat petri dish, the solvent was allowed to escape under a nitrogen gas atmosphere at room temperature, and the film thickness was 52.6 μm and was semitransparent. A cast film b was obtained. The cast film b had no cavities in its cross section, and the front and back surfaces were smooth. In addition, as a result of measuring the gas permeability of the cast film b, oxygen was found to be a few
100 ml / m ² / day, nitrogen 560 ml / m ² / day, carbon dioxide showed 14,500ml / m ² / day.

[0041]

According to the present invention, a porous polypeptide film or sheet having excellent water vapor permeability is provided.

Claims (11)

[Claims] 1. A casting film of a synthetic polypeptide, an organic solvent capable of dissolving the synthetic polypeptide, a volatile organic solvent compatible with the organic solvent capable of dissolving the synthetic polypeptide and miscible with water, and water. A porous film or sheet obtained by the above. 2. A synthetic polypeptide solution comprising a synthetic polypeptide and an organic solvent dissolving the synthetic polypeptide, and a volatile organic solvent miscible with water and miscible with the organic solvent dissolving the synthetic polypeptide. The porous film or sheet according to claim 1, which is a mixed liquid obtained by mixing an aqueous solution containing water. 3. A volatile liquid which is mixed with 30 parts by weight of a synthetic polypeptide solution consisting of a synthetic polypeptide and an organic solvent dissolving the synthetic polypeptide, an organic solvent dissolving the synthetic polypeptide and miscible with water. The porous film or sheet according to claim 2, which is a mixed solution containing 1 to 40 parts by weight of an aqueous solution containing an organic solvent and water. 4. A synthetic polypeptide solution comprising a synthetic polypeptide and an organic solvent capable of dissolving the synthetic polypeptide has a synthetic polypeptide concentration of 2 to 10% by weight and is compatible with an organic solvent capable of dissolving the synthetic polypeptide. And the water concentration of the solution composed of water and a volatile organic solvent miscible with water is 5 to 6
The porous film or sheet according to claim 2 or 3, which is 5% by weight. 5. The porous film or sheet according to claim 1, wherein the synthetic polypeptide is a synthetic polypeptide having an α-helix forming ability. 6. The porous film according to claim 1, wherein the organic solvent that dissolves the synthetic polypeptide is at least one solvent selected from the group consisting of 1,2-dichloroethane, dichloromethane, chloroform, tetrachloroethane and benzene. Or sheet. 7. A volatile organic solvent compatible with an organic solvent capable of dissolving a synthetic polypeptide and miscible with water is methanol,
The porous film or sheet according to claim 1, which is one or more solvents selected from ethanol, n-propanol and isopropanol. 8. A water vapor transmission rate of 4,000 to 10,000.
The porous film or sheet according to claim 1, 2 or 3, which has a concentration of 0 (g / m ² / day). 9. The film thickness of 3 to 150 μm,
The porous film according to 2 or 3. 10. A casting film of a synthetic polypeptide, an organic solvent capable of dissolving the synthetic polypeptide, a volatile organic solvent miscible with the organic solvent capable of dissolving the synthetic polypeptide and miscible with water, and water. To produce a porous film or sheet. 11. A synthetic polypeptide solution comprising a synthetic polypeptide and an organic solvent dissolving the synthetic polypeptide, and a volatile organic solvent compatible with the organic solvent dissolving the synthetic polypeptide and miscible with water, The production method according to claim 10, which is a mixed liquid obtained by mixing a solution composed of water.