JPH04339827A - Deposition and granulation of partially hydrolyzed keratin - Google Patents

Abstract

PURPOSE:To deposit partially hydrolyzed keratin by partially cleaning the cystine bonds of keratin of, e.g. wool and to granulate the partially hydrolyzed keratin into small porous spheres. CONSTITUTION:Keratin of, e.g. wool is immersed in warm water, and a dilute alkali solution is added to this water and agitated for several tens of min under heating to obtain a viscous solution. This solution is added dropwise to a dilute hydrochloric acid solution kept at a pH of about 6 or below under agitation. The deposited partially hydrolyzed keratin is washed with water under agitation and neutralized to a pH of about 6-7. After the product is dewatered and dried after water washing, it is formed into granules which can be pulverized on a known jet mill.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a method for precipitating a partial decomposition product of keratin by partially cleaving cystine bonds in keratins such as wool. The present invention relates to a method for granulating into small spheres.

0002

BACKGROUND OF THE INVENTION It has been widely practiced in the past to powder wool fibers and use them as raw materials for cosmetics, heavy metal adsorbents, synthetic leather additives, and the like. for example,
JP-A No. 55-84558 discloses that wool fibers are made into felt by shrinkage treatment, then pelletized and formed to have an apparent specific gravity above a certain level, and then processed in a low-temperature grinding device such as a hammer mill that is cooled to below -40°C. Grind in the presence of liquid nitrogen. The obtained wool fiber powder is a fine powder of about 10 to 80 μm.

Furthermore, in JP-A-57-163392, keratin materials such as animal hair and feathers are brought into contact with an aqueous solution containing a surfactant such as an alkylbenzene sulfonate, and the resulting hydrated keratin material is heated to -80°C. It is frozen below and further pulverized by a friction method or an impact method to prepare a fine powder. The powder of keratin material is colorless, odorless and has uniform properties.

0004

[Problems to be Solved by the Invention] In both of the above methods, the former requires the use of liquid nitrogen and the cooling of a low-temperature grinding device such as a hammer mill to below -40°C, while the latter requires the use of liquid nitrogen to cool the keratin material to below -40°C. Since it is necessary to freeze the water-containing material at -80° C. or lower, an expensive freezing device must be installed, and the cost of the device becomes extremely high.

On the other hand, the method of JP-A-3-45786 supplies steam under pressure to sufficiently humidify the inside of the wool fibers, and then releases the pressure to make the wool fibers brittle. Grind and separate using a crusher. These methods are
Since the manufacturing process of protein powder is complicated and the production efficiency is not high, the manufacturing cost of the obtained powder is very high.

[0006] Furthermore, since the protein powders produced by the above methods are all made by directly pulverizing the wool or hair itself, they can only be pulverized to a particle size of about 20 μm due to the strong bonds of their molecular structures, which can be further refined. Pulverization requires a huge amount of energy, making it expensive, and even if it is pulverized, there is a risk that the protein molecules themselves may be destroyed. The obtained protein powder was crushed by impact using a hammer mill, etc., so the particle structure when magnified under a microscope has sharp points.

On the other hand, it is well known that when wool fibers are treated with a dilute aqueous alkaline solution, they undergo so-called hypershrinkage, in which they are more bent and folded than α-keratin. When wool is treated with alkali or heat, it produces a secondary amino acid, lanthionine, which is not found in natural wool, and is also known to be induced by cleavage of the disulfide bond of cystine (Large Organic Chemistry). Volume 21, Natural Polymer Compounds III, pages 541-542, published by Asakura Shoten).

Since wool keratin is difficult to dissolve without decomposition, it has already been disclosed that if the cystine bonds between keratin molecules are cut or partially oxidized, most of the wool keratin can be dissolved in a dilute aqueous ammonia solution. However, when wool fibers are heated and treated with alkali to liquefy,
It was generally believed that the hydrogen bonds and cystine bonds in wool keratin are broken appropriately and the wool is immediately decomposed into various amino acids without producing a partial decomposition product of keratin, which is a high-molecular protein.

Therefore, even if wool fibers are liquefied by alkali treatment, it is not possible to precipitate a suitable partial keratin decomposition product using a dilute acid solution. It was thought to be impossible to obtain.

The present invention overturns the conventional idea regarding partial decomposition and powderization of keratin such as wool, and by adding a dilute alkaline solution to keratin and stirring for an appropriate time under an appropriate heating condition, The object of the present invention is to provide a method for precipitating a partially decomposed keratin product that has been partially cleaved from raw material keratins but is still a polymer.

Another object of the present invention is to convert solid keratin partial decomposition products, which are high-molecular proteins, into porous small particles so that they can be conveniently used as cosmetic raw materials, heavy metal adsorbents, synthetic leather additives, etc. An object of the present invention is to provide a method for granulating into spheres.

0012

[Means for Solving the Problems] In order to achieve the above object, in the precipitation method according to the present invention, keratin is immersed in warm water, a dilute alkaline solution is added thereto, and the mixture is stirred for several tens of minutes in a heated state. to obtain a viscous liquid. Keratins, which are raw materials, include wool, animal hair, hair, feathers, etc., such as wool and feathers contained in pure wool or blended clothing, carpets, blankets, futons, etc., or waste from barber shops and beauty salons. It may also be hair, etc.

[0013]The dilute alkaline solution used is generally an aqueous alkali hydroxide solution such as sodium hydroxide or potassium hydroxide, but it is possible that other dilute alkaline solutions can also be used. The concentration of the dilute alkaline solution may be around 2% by weight after being added to the keratin.
Increase or decrease as appropriate depending on the type of keratin and dilute alkali, heating and stirring conditions, etc.

[0014] The hot water for soaking keratins is usually 50%
It is heated to ~90°C, and the temperature when adding and stirring the dilute alkaline solution may be maintained at about 60 to 80°C. Further, the solution is stirred until the keratin is almost completely dissolved, and the stirring time is approximately several tens of minutes, usually 10 minutes.
~40 minutes.

[0015] The viscous liquid obtained by dissolving keratins is
It is added dropwise with stirring into a dilute acid solution whose pH is maintained at about 6 or less to precipitate a yellow-white keratin partial decomposition product. If the viscous liquid contains impurities, it may be filtered before dropping into the dilute acid solution. The viscous liquid is preferably dropped into a large volume of dilute acid solution, for example at a pH of about 3-4. The dilute acid solution used is generally an aqueous solution of acetic acid, hydrochloric acid, etc., but it is possible that other acid solutions can also be used.

The precipitated keratin partial decomposition product is further washed with water while stirring to neutralize it to a pH of approximately 6 to 7, and then dehydrated and dried to granulate the keratin partial decomposition product to a particle size of approximately 3 mm. . After dehydration and drying, the keratin partially decomposed product is further pulverized using a known jet mill to form porous small spheres with a particle size of 10 μm or less and an average of about 5 to 6 μm.

[0017]

[Operation] In order to dissolve keratins such as wool in a dilute alkaline aqueous solution, it is necessary to cleave or partially oxidize the cystine bonds between keratin molecules. When a dilute alkaline solution is added to the keratin and stirred for 10 to 40 minutes while maintaining the temperature at approximately 60 to 80°C, the hydrogen bonds and cystine bonds in the keratin are appropriately broken and the keratin is dissolved. can.

In the case of wool keratin, the obtained keratin partial decomposition product is not degraded to various amino acids, and is still a high-molecular protein, although it has a lower molecular weight than the raw material keratin, which has a molecular weight of several tens of thousands. When the precipitated keratin partial decomposition product is pulverized, the keratin partial decomposition product becomes porous small spheres with a particle size of 10 μm or less and an average of about 5 to 6 μm, which is compared to the particle size of about 20 μm that is possible with conventional methods. Much more detailed.

[0019]

EXAMPLES Next, the present invention will be explained based on examples. Example 1 1 kg of suitably cut wool is immersed in 8 liters of warm water at 50 to 90°C, and 2 liters of 8 wt% caustic soda is added to it.
Add in liters. When this solution is stirred for 20 minutes while maintaining the liquid temperature at 60° C., the fiber lumps disappear and a viscous liquid free of impurities is obtained.

When this viscous liquid is dropped into a large amount of dilute acetic acid aqueous solution with stirring at a pH of about 3 to 4, a sulfur odor is generated, indicating that the cystine bonds in wool keratin are being severed over time. It is clear that a yellow-white keratin partial decomposition product is finally precipitated. The precipitated keratin partial decomposition product is further washed with water while stirring to neutralize it to a pH of about 6 to 7, passed through a mangle, compressed and dehydrated, and then dried to obtain a keratin partial decomposition product.

[0021] When the molecular weight of the obtained keratin partial decomposition product is measured using an ultracentrifugation method, it is found that the amino acids that make up wool keratin have not been degraded, and although it has a lower molecular weight than wool keratin, which has a molecular weight of several tens of thousands, it is similar to keratose. It is a high molecular weight protein. Wool powder, which is a partially decomposed product of keratin, is granulated by stirring during solidification, and thus has a coarse particle size of up to about 3 mm.

[0022] This wool powder is granulated by stirring during solidification, so that the particle structure when magnified under a microscope is approximately spherical. This wool powder can be used as a heavy metal adsorbent.

Example 2 The partially decomposed keratin product having a particle size of approximately 3 mm produced in Example 1 is pulverized by a jet mister after drying. In the jet miser used, particles of partially decomposed keratin are fed into a high-speed air stream (jet), and are ultrafinely pulverized by collision and friction between the particles or between the particles and the inner wall of the mill.

[0024] The obtained keratin partial decomposition product has a particle size of 90% or more of 10 μm or less, a moisture content of 4.5%,
H is 6.7. According to the JIS semi-micro Kjeldahl method, the N analysis value is 14.59%. The particles of this partially decomposed keratin are porous and spherical, as is clear from the 4000x electron micrograph shown in FIG.

[0025] This fine wool powder has a nearly spherical particle structure when magnified with an electron microscope, and is porous and small spherical with a particle size of 10 μm or less and an average of about 5 to 6 μm, so it can be used as a raw material for cosmetics, etc. can. When this fine wool powder is added to a milky lotion or face powder, the fine particles make the milky lotion or face powder spread better, making it easier to blend into the skin.

Example 3 Using a discarded pure wool pile carpet made of 100% wool as a raw material, the lining of the carpet was peeled off and the pile portion was taken out, and 1 kg of this pile portion was cut into several mm to 10 mm.
After cutting into pieces of about mm, the pieces are immersed in 8 liters of warm water at 50 to 90°C, and 2 liters of 8% by weight caustic soda is added thereto. When this solution is stirred for 20 minutes while maintaining the liquid temperature at 60° C., the pile fiber lumps disappear and a viscous liquid containing impurities is obtained.

After filtering this viscous liquid, when the viscous liquid is dropped into a large amount of dilute acetic acid aqueous solution with stirring to maintain the pH at about 3 to 4, a sulfur odor is generated and the cystine bonds in wool keratin are removed. As it is cut over time, a yellowish-white keratin partial decomposition product is finally precipitated. The precipitated keratin partial decomposition product is further washed with water while stirring to neutralize it to a pH of approximately 6 to 7, and then passed through a mangle to compress and compress it.
If it is dehydrated and then dried, a partially decomposed keratin product can be obtained.

The obtained keratin partial decomposition product was prepared in Example 1.
Similarly, the particle size is coarse grained up to about 3 mm,
It can be used as a heavy metal adsorbent. By this method, a large amount of unused pure wool carpet can be processed to obtain useful substances, and a large amount of industrial waste can be reused. Furthermore, since only a dilute alkaline solution and a dilute acid solution are used during this treatment, there is almost no risk of causing pollution.

Example 4 A needle-punch carpet made of a blend of 50% wool and 50% polyester fibers is used as a raw material, and the entire carpet is cut into pieces of several mm to about 10 mm. 50 to 90
It is immersed in 8 liters of warm water at a temperature of 100°C, and 8% by weight of caustic soda is added to 2 liters of it. When this solution is stirred for 20 minutes while maintaining the temperature of the solution at 60° C., the wool portion is dissolved leaving only the polyester fibers, and a viscous liquid is obtained.

The remaining polyester fibers may be removed by filtration and sent to a plastic recycling process. Meanwhile, the filtered viscous liquid is treated in the same manner as in Example 3 to obtain useful substances such as heavy metal adsorbents.

Example 5 General fulled felt made of wool and rayon (the wool content is usually 50% or more) was used as the raw material, and the felt was treated in the same manner as in Example 4, leaving only the rayon. The wool part dissolves and a viscous liquid is obtained. The remaining rayon is
Remove by filtration and discard. Meanwhile, the filtered viscous liquid is treated in the same manner as in Example 3 to obtain useful substances such as heavy metal adsorbents.

[0032]

Effect of the invention: The partially decomposed keratin product precipitated by the method of the present invention has hydrogen bonds and cystine bonds in keratins such as wool, animal hair, and hair properly broken, and has a molecular weight lower than that of the raw material keratin, which has a molecular weight in the tens of thousands. Although it is a molecule, it is still a high-molecular protein. Therefore, it can be used as a substitute for natural proteins in cosmetic raw materials, medical materials, heavy metal adsorbents, synthetic leather additives, etc., and can also be used in general synthetic protein applications.

After the obtained keratin partial decomposition product is dehydrated and dried, it is further pulverized using a known jet mill, and the keratin partial decomposition product has a particle size of 10 μm or less and an average of about 5 to 6 μm.
m into porous globules. This protein substance is a spherical fine particle, so when it is used as a raw material for cosmetics and added to emulsions and face powders, it spreads easily and blends into the skin.

[0034] Furthermore, by using the method of the present invention, useful substances can be obtained by processing a large amount of disused carpet, etc., which is beneficial in terms of reusing industrial waste. Since only a dilute alkaline solution and a dilute acid solution are used, there is no risk of pollution.

[Brief explanation of drawings]

FIG. 1 is an electron micrograph at 4000 times magnification showing particles of partially decomposed keratin granulated by the method of the present invention, and the length of the straight line at the bottom of the photograph is 10 μm.

Claims (3)

[Claims] Claim 1: Keratin such as wool is soaked in warm water, a dilute alkaline solution is added thereto, and the mixture is stirred for several tens of minutes in a heated state to obtain a viscous liquid, and the viscous liquid has a pH of about 6 or less. A method in which a yellowish-white partially decomposed product of keratin is precipitated by dropping it dropwise while stirring into a dilute acid solution maintained at a constant temperature. [Claim 2] Keratin such as wool is soaked in warm water, a dilute alkaline solution is added thereto, and stirred for several tens of minutes in a heated state to obtain a viscous liquid, and the viscous liquid is soaked in a dilute acid solution. A method of granulating a partially decomposed keratin product by precipitating a partially decomposed keratin product by dropping it dropwise while stirring, and washing the precipitate with water while stirring to neutralize it to a pH of about 6 to 7. 3. Keratin such as wool is soaked in warm water, a dilute alkaline solution is added thereto and stirred for several tens of minutes in a heated state to obtain a viscous liquid, and the viscous liquid is soaked in a dilute acid solution. A method of granulating a partially decomposed keratin product by depositing it dropwise while stirring, washing it with water, dehydrating it, drying it, and then pulverizing it with a known jet mill.