JPH04226538A - Production of collagen powder - Google Patents

Abstract

PURPOSE:To provide collagen powder suitable as an additive for improving coatings, artificial leathers, molding materials, etc., which contain thermoplastic resins as base raw materials. CONSTITUTION:A purified animal tissue containing collagen as a main component is subjected to a wet grinding treatment in a collagen concentration of 1-30wt.% at a water temperature of <=37 deg.C and in a pH range of 2-8 in water, and subsequently subjected to a tanning treatment using a multivalent metal tanning agent in a pH range of 4-8 to produce a wet stabilized collagen material, which is dehydrated at a pH of 4-8 and further dried and pulverized into the powder of collagen. The powder of the collagen can be employed in an additive for improving coatings, artificial leathers, molding materials, etc., which contain synthetic resins as a base material. The addition of the powder of the collagen thereto gives the materials having excellent performances such as excellent appearances, touches, moisture-absorbing and releasing properties.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel method for producing collagen powder. More specifically, the present invention relates to a method for producing collagen powder suitable for use as an additive useful in modifying paints, artificial leathers, molding materials, etc. based on synthetic resins such as thermoplastic resins.

0002

[Prior Art] In recent years, with the trend toward higher quality paints, artificial leathers, etc., there has been a demand for paints, artificial leathers, etc. to have the appearance, feel, moisture absorbing/releasing properties, moisture permeability, etc. of natural leather. Synthetic resins such as polyurethane resin, polyacrylic resin, and polyvinyl chloride resin, which are the base of artificial leather and molding materials, are mixed with collagen powder, leather powder, gelatin powder, polyurethane beads, etc., and modified to resemble natural leather. An attempt is being made to do so.

[0003] Several methods have been proposed for producing collagen powder and leather powder used in these products.
Most of them are chrome-tanned or tanned natural leather that is simply crushed and powdered, and these are tanned in the state of bare skin, that is, in the state of collagen fiber bundles. Because of that,
Even when powdered, it tends to become long fibers rather than particles, and as seen in Japanese Patent Publication No. 40-11075, for example, artificial leather manufactured by mixing these with thermoplastic resin loses its surface smoothness. There are problems such as the inability to obtain a natural leather-like feel. Recently, JP-A-63-992
As seen in Japanese Patent No. 98, in order to improve these problems, a method has been proposed in which leather scraps are heat treated with steam and then ground into granular powder. However, with this method, the leather powder becomes particulate, but it is heated to 100℃ using steam.
Because it is heated to a higher temperature, it becomes a powder with low hygroscopicity and high apparent bulk specific gravity (JIS K 6721). For example, when this is used as an additive for paint, it may cause the surface to become matte or the moisture absorption/release properties to be reduced. It has drawbacks such as lack of effectiveness, and it is still difficult to say that it is satisfactory.

[0004] Furthermore, Japanese Patent Publication No. 61-4419 proposes a method of powdering collagen instead of leather waste. In this method, collagen powder is obtained by sequentially performing coarse dispersion, tanning, dispersion, dehydration, and drying using purified animal skin, and the collagen fiber bundles obtained by coarse dispersion are tanned. Therefore, the collagen becomes fibrous, resulting in the same problem as in Japanese Patent Publication No. 40-11075.

Furthermore, Japanese Patent Application No. 1-217499 discloses that after pulverizing animal tissue whose main component is collagen purified by a special method in water, it is tanned with a tanning agent to obtain wet collagen. A method for producing collagen has been proposed, but pulverizing animal tissue in water produces a collagen concentration of 0.3.
Since it is done at low concentrations such as ~0.8% by weight,
There are problems in that pulverization takes a long time or the collagen fiber bundles are insufficiently defibrated, resulting in long fibers being mixed into the powder.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a material that has a low apparent bulk density, does not contain fibrous materials, is particulate, and can be used in paints, artificial leather, etc. The object of the present invention is to provide a method for producing collagen powder that can be added to synthetic resins that are the base of molding materials and the like to impart properties similar to those of natural leather.

[0007]

[Means for solving the problem] As a result of intensive studies to achieve the above object, we have developed a purified animal tissue obtained by treating animal tissues such as naked skins of pigs, cows, etc. with lime pickling, enzyme treatment, washing with water, etc. The resulting collagen mass was shredded and further submerged in water.
By wet milling at a collagen concentration of 1 to 30% by weight, a water temperature of 37°C or less, and a pH of 2 to 8, a collagen fibril dispersion or dissolution can be efficiently obtained, and this can be used as a tanning agent for conventional skin peels. Polyvalent metal salts such as chromium sulfate, aluminum sulfate, and zirconyl sulfate, which are used as tanning agents, are added at a pH range of 2 to 7 to form a stabilized collagen wet mass, and then the pH is adjusted to a pH range of 4 to 8. By adjusting, dehydrating, further drying and pulverizing, it was found that a collagen powder having a low apparent bulk density but in which the collagen is not fibrous but granular was obtained, leading to the completion of the present invention.

[0008] In the method for producing collagen powder of the present invention, in order to obtain the collagen powder as described above, a purified collagen mass is shredded, wet-pulverized in water, and tanned to form a collagen wet powder. Based on the viewpoint that it is necessary to uniformly tan collagen and to suppress collagen hydrolysis (gelatinization) as much as possible in the process of After fully wet-pulverizing the animal tissue as a component in water to a concentration of 1 to 30% by weight, more preferably 3 to 15% by weight, to obtain a fine fiber dispersion or a dissolved substance,
Adding a tanning agent to the tanning process, and wet grinding at a pH of 2 to 8 and a temperature of 37 degrees Celsius or less, using a polyvalent metal tanning agent in the tanning process at a pH of 2 to 7, and dehydrating to a pH of 2 to 7. It is characterized by manufacturing under narrowly limited conditions such as adjusting the value to 4 to 8.

The present invention will be further explained in detail. That is, the present invention is a method for producing collagen powder by sequentially dispersing or dissolving animal tissue such as purified animal skin in water, tanning, dehydration, drying, and pulverization. As this animal tissue, tissues containing a large amount of collagen such as the skin, bones, tendons, etc. of all vertebrate animals including mammals such as cows, horses, pigs, and sheep can be used, and there are no particular restrictions on the purification method. , a method using one or more types of enzymes such as protease and lipase, a method using an alkali such as lime, and a method using an ionic or nonionic surfactant. It is preferable to use naked animal hides that have been thoroughly cleaned of impurities by treatment with a surfactant. In addition, the surfactant used here is not an ionic one that tends to remain in naked skin even after washing.
Preferably, non-ionic materials are used.

[0010] Dispersion or dissolution by wet pulverization is intended to make the properties of the collagen powder constant, prevent it from forming into long fibers, and at the same time make the tanning treatment that follows the wet pulverization process easier. In addition, in order to make the collagen uniform, the purified collagen mass is swollen with water to form a dispersion or melt of collagen fibrils.

[0011] The purified animal tissue is roughly cut using a meat grinder, etc., and then diluted with water to bring the collagen concentration to 1.
-30% by weight, pH is adjusted to 2-8, and the water temperature is adjusted to not exceed 37°C using equipment such as a paper-making beater or a rotary blade crusher. If the concentration of collagen is less than 1% by weight, the wet grinding will not be sufficiently uniform, the residual portion of fiber bundles will increase significantly, and the efficiency of the wet grinding will decrease significantly, which is not preferable. Additionally, if the concentration of collagen exceeds 30% by weight, the viscosity of the dispersion will increase and the water temperature will rise to 37°C or higher during wet milling, causing collagen hydrolysis, so the milling speed should be slowed down. This is not preferable because it requires measures such as the following, which significantly reduces the efficiency of pulverization.

[0012] The pH at this time is selected within the range of pH 2 to 8 to determine the properties of collagen.
Furthermore, physical properties such as the apparent bulk density of the collagen powder can be determined. That is, when the pH is increased within the range of pH 2 to 8, collagen becomes a fibrous dispersion, and the apparent bulk specific gravity of the powder becomes low; when the pH is decreased, collagen becomes a strongly swollen or dissolved material, and the powder becomes less dense. The apparent bulk density can be increased.

[0013] However, if the pH is less than 2 or more than 8, hydrolysis of collagen tends to occur during the wet grinding process, which is not preferable. The acids and alkalis used to adjust the pH here may be those commonly used. Examples of acids include mineral acids such as hydrochloric acid and sulfuric acid, acetic acid, lactic acid, citric acid, tartaric acid, succinic acid, malic acid, etc. Any of the organic acids may be used, and as alkalis, sodium hydroxide, sodium bicarbonate, aqueous ammonia, organic amines, etc. can be used.

[0014] The tanning process depends on the water absorption of collagen powder {
Since no standardized measurement method has been established at present, the following method was used for measurement. Powder sample approx.
After soaking 0g (WA) in water for over 1 hour to absorb water, drain the water thoroughly and add filter paper (No. 5 manufactured by Toyo Roshi Co., Ltd.).
Cφ9cm) to a diameter of approximately 4cm, and after layering several pieces of filter paper above and below this, a 20kg weight was placed on top of these and dehydrated under pressure for 3 minutes to remove excess adhering water.
Weigh (WB) and use the following formula: Water absorption = (WB - WA)
/WA×100 (weight%). } for the purpose of maintaining a predetermined value and increasing heat resistance stability, a tanning agent is added to a dispersion or melt of collagen fibers, and the tanning agent is deposited between fibers or molecules, or between fibers or molecules. This is a process that connects the two.

[0015] Tanning agents include polyvalent metal compounds such as chromium sulfate, zirconyl sulfate, and aluminum sulfate, but in addition to these, it is also possible to use organic compound tanning agents such as formaldehyde, glutaraldehyde, and tannin. It is. By using a polyvalent metal tanning agent as the main ingredient of the tanning agent, it is possible to considerably raise the thermal denaturation temperature of collagen, so high temperatures can be used in the dehydration and drying steps in the post-processes, and the It will be possible to improve efficiency. Furthermore, by changing the amount of tanning agent added, it is possible to change the water absorption of the collagen powder.

[0016] For example, the amount of tanning agent necessary to achieve a water absorption of 150 to 300% by weight, which is preferable as an additive for paints, artificial leather, molding materials, etc., is 1 to 2 parts by weight for chromium sulfate per 100 parts by weight of collagen. 1 to 10 parts by weight for zirconyl sulfate and 2 to 20 parts by weight for aluminum sulfate. In addition, when it is desired to make the appearance of collagen powder white, it is preferable to use zirconyl sulfate or aluminum sulfate as a tanning agent.

Furthermore, the pH of the collagen dispersion is 2 to 7.
The tanning process is carried out at a pH of less than 2.
If the metal tanning agent becomes difficult to deposit between collagen fibers, or the carboxyl groups in collagen do not dissociate and bonding with the tanning agent becomes very slow, or if the pH exceeds 7, acetic acid, citric acid, lactic acid This is because even in the presence of organic acid ions such as tanning agents, polyvalent metal ions in the tanning agent precipitate as hydroxides upon addition, resulting in uneven tanning. Furthermore, in the tanning process, it is also possible to add pigments such as titanium dioxide and iron oxide, and extender pigments such as kaolin and silica to obtain collagen powder that is colored or has a different hardness.

[0018] The dehydration treatment is carried out using a conventional centrifuge, filter press, screw press, etc., in order to lower the moisture content of the collagen aggregates obtained during the tanning treatment and to facilitate drying. . At this time, dehydration is performed by adjusting the pH to a range of pH 4 to 8. This is because if the pH is less than 4 or exceeds pH 8, hydrolysis of collagen tends to occur during drying. This is because collagen powder becomes acidic or alkaline, so when it is mixed with a synthetic resin, etc., the resin tends to be hydrolyzed, which significantly impairs the physical properties of the product.

[0019] There is no particular limit to the temperature of the stabilized collagen wet body during dehydration, but if it is heated to about 70°C or higher, the collagen wet body will coagulate, expel some of the retained water, and This is preferred because the dehydration efficiency increases. However, heating the collagen wet body above the heat denaturation temperature, which is determined by the type and amount of tanning agent used, must be avoided as this will cause collagen hydrolysis.

[0020] The drying process is performed using a fluid type, tray type, belt type, or paddle type in order to further reduce the moisture content of the wet collagen that has become lumpy due to the dehydration process and to facilitate the pulverization process. This is done by a conventional method using a dryer such as a spray type dryer. In order to carry out the pulverization treatment, the moisture content is preferably 10% by weight or less.

[0021] The pulverization process is carried out using a conventional jet mill, hammer mill, or
This is done using a ball mill, etc. The properties of the powder produced vary depending on the purpose for which it is used, but in general, the particle size is close to a normal distribution, with a median diameter of 4 to 25 μm, and a particle size of 40 μm.
It is preferable that 85% or more be less than μm. (The particle size and particle size distribution of the powder were measured by the Coulter counter method.) The collagen powder produced in this way is
Unlike leather powder obtained by simply pulverizing leather produced by tanning purified bare skin, collagen fiber bundles are completely defibrated or dissolved by pulverization in water and then aggregated by tanning. Because it is made up of
It is characterized by a low apparent bulk specific gravity.

[0022] If wet milling and tanning are performed under the above conditions while collagen is precipitated, a collagen powder with high water absorption and particularly high oil absorption (JIS K 5101) can be obtained. If the oil absorption of collagen powder is low, it may be mixed with synthetic resins etc. and used in paints, artificial leather, etc.
When used as a molding material, due to the difference between the true specific gravity of the collagen powder and the specific gravity of the resin solution in the resin or its solution, the collagen powder will settle and solidify into a cake, making redispersion impossible, resulting in poor dispersion stability. Collagen powder with high oil absorption is particularly useful in the above points as well.

[0023] Also, the state in which collagen is precipitated is
Collagen is not dissolved or swollen in water, but is precipitated in the form of fibers, or is in the form of a slurry, and the precipitation form may be either regular aggregates or amorphous aggregates. Furthermore, in order to obtain a state in which collagen is precipitated, the pH should be adjusted to a value higher than the isoelectric point of collagen, or
Alternatively, collagen may be salted out using salts such as sodium chloride or sodium sulfate, but these two methods may be used in combination.

[0024] The isoelectric point of collagen mentioned here is
This is the pH value at which the + (plus) charges and - (minus) charges that exist in collagen are exactly canceled out, and the collagen appears to be uncharged. When animal skin is purified by alkali treatment, the isoelectric point pH is generally between pH 4 and 5. Adjusting the pH above the isoelectric point means adjusting the pH
is higher than 4 to 5.

[0025]

[Action] Collagen powder produced by the method of the present invention can be mixed with paints, artificial leathers, and molding materials based on synthetic resins such as polyurethane resins, polyester resins, polyacrylic resins, and polyvinyl chloride resins. It is possible to obtain paints, artificial leathers, and molding materials that have natural leather-like appearance, feel, and performance such as moisture absorption and desorption properties.

For example, in paints, as a typical example,
It is prepared by adding 30 to 200 parts by weight of collagen powder to 100 parts of the solid content of the paint based on a polyurethane resin paint, dispersing it well, and adding a solvent as necessary to make an appropriate concentration. It is used by coating with a coater, etc. In the case of artificial leather, as a typical example, 30 to 200 parts by weight of collagen powder is added to 100 parts by weight of polyurethane resin and kneaded, and this is used by laminating it on a polyvinyl chloride sheet or a nonwoven fabric sheet. The molding material is typically used by adding 30 to 200 parts by weight to 100 parts by weight of a polyurethane resin, kneading the mixture, and molding it using an extruder or the like, similar to artificial leather. All of these have excellent appearance, feel, moisture absorption and desorption properties similar to natural leather. The present invention will be explained in more detail by the following examples.

[0027]

[Example] Example 11) Purification and wet pulverization treatment 500 parts by weight of cow hide (dry amount is 100 parts by weight, hereinafter abbreviated as parts), which was washed with water after being treated with alkali with lime,
Papain was soaked in the following treatment solution whose pH was adjusted to 8.1 with sodium bicarbonate.
0.60 parts pancreatin
0.15 parts L-glutamic acid
0.35 part Sodium chondroitin sulfate 0.003 part L-potassium hydrogen tartrate 0.35 part Triton X
-100 * 0.50 part water

5,000 parts*; Nonionic surfactant (trade name of polyoxyethylene-alkylphenyl ether) Stir in a household washing machine at room temperature for 12 hours to remove impurities, then wash with water, and remove lactic acid. The purified collagen tissue obtained by adjusting the pH to 3.5 was minced using a meat grinder, and the dry weight concentration of the original bed skin was 3.5%.
The mixture was diluted with water (pH 4.0) and wet-pulverized using a paper mill at a water temperature of 25°C.

2) Tanning treatment After the wet grinding treatment, the following tanning agents were sequentially added in a paper beating machine (pH 3.8).
Basic aluminum sulfate 4.5 parts zirconyl sulfate 2.5 parts Tanning treatment was carried out to obtain a stabilized collagen wet body.

3) Dehydration, drying, and pulverization After adjusting the pH of the stabilized collagen wet body obtained by tanning to 6.0 with sodium bicarbonate, the moisture content was reduced using a screw press dehydrator. After dehydrating to 67% by weight, it was dried using a hot air tray dryer to give a moisture content of 9.5% by weight, and then ground using a ball mill to obtain the physical properties shown in Table 1. It was made into collagen powder.

Example 2 1) Purification and Wet Grinding 500 parts (dry weight: 100 parts) of cow bedding skin that had been alkali treated with lime and washed with water were
Soaked in the following treatment solution whose pH was adjusted to 9.0 with ammonium sulfate, and papain 0
．． 55 parts pancreatin
0.15 parts L-potassium hydrogen tartrate 0.3
0 parts Triton X-100 0.50
Department water
5,000 copies were stirred in a household washing machine at room temperature for 12 hours to remove impurities, and after further washing with water, the purified collagen tissue obtained by adding lactic acid to adjust the pH to 4.0 was passed through a meat grinder. This was minced using water, diluted with water so that the weight concentration of the dry amount of raw hide was 6.0%, the pH was adjusted to 3.2 with lactic acid, and the mixture was decomposed with a rotary blade. Wet pulverization was performed using a pulverizer at a water temperature of 30°C.

2) Tanning treatment After wet grinding, the following tanning agents were sequentially added in a household mixer (pH 3.0) to carry out tanning treatment using 2.5 parts of basic aluminum sulfate and 3.0 parts of zirconyl sulfate. A stabilized collagen wet body was obtained.

3) Dehydration, drying, and pulverization The stabilized collagen wet body obtained through the tanning process was adjusted to pH 7.0 using sodium hydroxide, heated to 70°C, and then dried using a centrifugal dehydrator. After dehydration until the moisture content becomes 65% by weight, it is dried using a fluidized fluid dryer to reduce the moisture content to 5.0% by weight, and then pulverized using a jet mill to obtain the physical properties shown in Table 1. It was made into collagen powder.

Example 3 (Wet grinding and tanning treatment in a state where collagen is precipitated) 1) Purification and wet grinding treatment 500 parts of cow bedding skin (dry weight: 1
00 parts) in the following treatment solution whose pH was adjusted to 8.1 with sodium bicarbonate, and papain
0.60 parts pancreatin
0.15 parts L-glutamic acid
0.35 part Sodium chondroitin sulfate 0.003 part L-potassium hydrogen tartrate 0.35 part Triton X
-100 0.50 part water

5,000 copies were stirred in a household washing machine at room temperature for 12 hours to remove impurities, and after further washing with water, the purified collagen tissue obtained by adding lactic acid to adjust the pH to 4.0 was passed through a meat grinder. This was minced using water, diluted with water so that the dry weight concentration of the original skin was 12.5%, and the pH was adjusted to 7.3 with sodium bicarbonate to extract collagen fibers. It was precipitated and wet-pulverized using a paper mill at a water temperature of 20°C.

2) Tanning After wet grinding, the following tanning agents were sequentially added in a household mixer (pH 6.7) with collagen precipitated, and 4.5 parts of basic aluminum sulfate and 2.5 parts of zirconyl sulfate were added. A stabilized collagen wet material was obtained by partial tanning.

3) Dehydration, drying, and pulverization The stabilized collagen wet body obtained through the tanning process was dehydrated at pH 5.3 using a screw press dehydrator until the moisture content reached 69% by weight, and then heated in a hot air rack. It was dried using a stage dryer to have a moisture content of 1.2% by weight, and then ground using a hammer mill to obtain collagen powder having the physical properties shown in Table 1.

Comparative Example 1 (method of wet pulverization with low collagen concentration) 1) Purification and wet pulverization treatment The concentration during wet pulverization was 0.7
Purification and wet pulverization were carried out in the same manner as in Example 1 except that the weight % was used. 2) Tanning Treatment After the wet grinding treatment, tanning treatment was performed in the same manner as in Example 1 to obtain a stabilized collagen wet body. 3) Dehydration;
The stabilized collagen wet body obtained by drying, crushing and tanning was adjusted to pH 6.3 using sodium hydroxide, and then dehydrated using a screw press dehydrator until the moisture content reached 72% by weight. It was dried using a hot air tray dryer to have a moisture content of 9.0% by weight, and then ground using a jet mill to obtain collagen powder having the physical properties shown in Table 1.

Comparative Example 2 (Method of Grinding Leather Scraps) Normal chrome-tanned leather scraps were shredded, heated to 110°C for 3 hours in an autoclave with heated steam, swollen, and dried in the same manner as in Example 1. The powder was ground into leather powder having the physical properties shown in Table 1.

Comparative Example 3 (Method of treating a fiber bundle dispersion with an organic tanning agent) 1) Purification and coarse dispersion treatment 500 parts of cow's bedding skin (dry amount: 10
0 parts) was adjusted to pH 9.0 with ammonium sulfate, immersed in the following treatment solution, and papain 0
．． 55 parts pancreatin
0.15 parts L-potassium hydrogen tartrate 0.3
0 parts Triton X-100 0.50
Department water
5,000 copies were stirred in a household washing machine at room temperature for 12 hours to remove impurities, further washed with water, and the resulting purified collagen tissue was added to a meat grinder to adjust the pH to 5.0. This was ground into minced pieces using a dispersion mill, and this was then diluted with a 15% by weight aqueous sodium sulfate solution so that the weight concentration of the dry weight of the raw skin was 4.0%, and further mixed with carbonate. The pH was adjusted to 8.5 with sodium to obtain a crude dispersion.

2) Tanning treatment 0.5 g of glutaraldehyde was added to the roughly dispersed collagen fiber bundle dispersion.
A time tanning treatment was carried out, and after washing with water, the total amount was 5000 parts (dispersion concentration: 2.0%). 3) Dispersion Treatment The pH of the tanned dispersion was adjusted to 5.0 with hydrochloric acid, and then redispersed using a dispersion mill to obtain a collagen fiber dispersion.

4) Dehydration, drying, and pulverization The collagen fiber dispersion obtained by redispersion was dehydrated using a screw press dehydrator until the moisture content reached 69% by weight, and then dried using a hot air tray dryer. and dried to a moisture content of 9.5% by weight.
This was further ground using a hammer mill to obtain collagen powder having the physical properties shown in Table 1.

Application test examples Examples 1, 2 and 3, comparative example 2
Using the collagen powder or leather powder obtained in A. and 3, respectively, A. Paint, B. Artificial leather, C. The results shown in Table 1 were obtained by applying the test to molding materials and conducting tests on the items shown in Table 1. However, since the powder of Comparative Example 1 had a high proportion of long fibers, it could not be used for application tests.

A. Add 5 parts of collagen powder to a resin solution prepared by dissolving 100 parts of paint polyurethane resin in 200 parts of ethyl acetate.
0 parts was added and dispersed well to obtain a clear paint. This paint was applied using a spray gun until the thickness of the paint layer after drying was 5.
It was coated on the surface of a transparent polycarbonate plate to a thickness of 0 μm and dried.

B. 50 parts of collagen powder and 8 parts of carbon black were added to a resin solution in which 100 parts of artificial leather polyurethane resin was dissolved in 200 parts of ethyl acetate, and the mixture was well dispersed to obtain a surface treatment agent. This treatment agent is applied to the surface of release paper using a gravure coater so that the thickness of the coating layer after drying is 30 μm, dried, an adhesive layer is provided on this surface, and it is attached to a nonwoven fabric sheet to create an artificial Made of leather.

C. Molding material polyurethane foam resin 100
After adding 50 parts of collagen powder and 8 parts of carbon black to the mixture and thoroughly kneading the mixture, the mixture was melt-molded into a sheet using a melt-molding machine to obtain a molded product sheet.

[0045]

[Table 1]

From the results in Table 1, it can be seen that the collagen powder produced by the method of the present invention has improved appearance, feel, and absorbency when used on any base material, compared to collagen powder produced by the conventional method. It has been shown that it has a high ability to improve performance such as moisture release. Furthermore, the clear paint prepared using the powder of Example 3 had better dispersion stability than any of the others.

[0046]

Effects of the Invention According to the present invention, collagen powder can be produced, and this powder can be used to produce materials with excellent performance in terms of appearance, feel, moisture absorption and desorption properties, etc. when applied to paints, artificial leathers, and molding materials.

Claims (2)

[Claims] Claim 1: Purified animal tissue containing collagen as a main component is wet-pulverized in water at a collagen concentration of 1 to 30% by weight, a water temperature of 37°C or less, and a pH of 2 to 8, and then processed into a polyvalent metal tanning agent. A stabilized collagen wet body is obtained by tanning the collagen at a pH range of 2 to 7, followed by dehydration at a pH range of 4 to 8, and further drying and pulverization to form a powder. Method of manufacturing powder. 2. The collagen powder according to claim 1, wherein the collagen powder is wet-milled and tanned in a state in which collagen is precipitated by adjusting the pH to a value higher than the isoelectric point of collagen or by salting out the collagen with salts. manufacturing method.