Modified regenerated collagen fiber, production method therefor, and headdress product containing the same

Abstract

To provide modified regenerated collagen fibers that improve water resistance and heat resistance under both dry and wet conditions, which are points at issue in regenerated collagen fibers, acquire thermal shape memory, improve elasticity (tenacity) and surface feel, and are free from coloring.SOLUTION: Modified regenerated collagen fibers comprise regenerated collagen fibers which contain either the ingredient (A) or a polymer comprising the ingredient (A) as its constituent monomer. (A): Vinylbenzoic acid or a salt thereof.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to regenerated collagen fibers imparted with water resistance, heat resistance, and heat shape memory ability, and preferably relates to regenerated collagen fibers used for fiber products such as headgear products such as wigs and extensions.

Background Art

[0002] Regenerated collagen fibers generally have a natural texture and appearance derived from natural materials, different from synthetic fibers. This regenerated collagen fiber is obtained by solubilizing acid-soluble collagen or insoluble collagen with an alkali or an enzyme to form a spinning dope, and discharging it through a spinning nozzle into a coagulation bath to be fibrillated.

[0003] However, regenerated collagen fibers generally have a higher hydrophilicity than synthetic fibers, so they have a high water absorption rate and extremely low mechanical strength when in a state containing a lot of water. For this reason, during washing, the mechanical strength is significantly reduced due to the high water absorption rate, leading to a decrease in suitability as fiber products such as headgear products, such as breaking during subsequent drying.

[0004] In addition, regenerated collagen fibers also have the problem of low heat resistance. For example, in a heat setting using a hair iron or the like, when set at a high temperature similar to human hair, shrinkage or curling occurs, deteriorating the appearance.

[0005] Furthermore, in plastic synthetic fibers, the shape during heat setting by an iron or the like is continuously remembered even after subsequent washing (it has heat shape memory ability), but in regenerated collagen fibers, the shape during heat setting by an iron or the like is lost after a single washing (it has no heat shape memory ability). Therefore, there is a disadvantage in terms of the degree of freedom of shape setting compared to conventional plastic synthetic fibers.

[0006] The above points have been factors hindering the spread of regenerated collagen fibers to fiber products. In particular, the influence of water resistance, that is, the decrease in mechanical strength when wet, has been significant. On the other hand, in the field of human hair fibers, a method is known in which a specific aldehyde derivative and a phenol compound are reacted with human hair fibers that do not inherently possess thermal shape memory ability to newly impart thermal shape memory ability (Patent Document 1). [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2019-143281 [Overview of the project] [Problems that the invention aims to solve]

[0008] However, in the manufacturing of textile products, fibers are sometimes stretched strongly, and the technology described in Patent Document 1 sometimes resulted in insufficient elasticity (toughness) of the treated fibers. Therefore, there was a need to improve the elasticity of the treated fibers to prevent breakage during stretching. In addition, the technology described in Patent Document 1 sometimes resulted in discoloration of the fibers.

[0009] Therefore, the present invention relates to a modified regenerated collagen fiber that has improved water resistance and heat resistance, which are problems with regenerated collagen fibers, and is given thermal shape memory ability, as well as having excellent elasticity (toughness) and surface feel, and is also colorless. [Means for solving the problem]

[0010] As a result of diligent research, the inventors have discovered that modified regenerated collagen fibers containing vinyl benzoic acid or its salts exhibit improved strength and heat resistance in water, while also preventing leakage of vinyl benzoic acid, its salts, or polymers from the fibers. This is because the vinyl benzoic acid polymerizes, and its carboxyl groups strongly coordinate with the metals (mainly polyvalent metals) in the regenerated collagen fibers. As a result, these modified regenerated collagen fibers exhibit improved water resistance and heat resistance in both dry and wet conditions, can be shaped by heat setting, and surprisingly, their elasticity (toughness) improves compared to before treatment, reaching a level close to that of human hair. Furthermore, there is no discoloration associated with the modification process, thus completing the present invention.

[0011] The present invention provides a modified regenerated collagen fiber containing the following component (A) or a polymer containing component (A) as a constituent monomer in the regenerated collagen fiber. (A) Vinylbenzoic acid or its salt

[0012] Furthermore, the present invention provides a method for processing regenerated collagen fibers, which includes the following step (i). Step (i) A step of immersing regenerated collagen fibers in a fiber treatment agent consisting of a single composition or a multi-component fiber treatment agent consisting of multiple compositions, the fiber treatment agent containing the following components (A) and (B) in its total composition. (A): Vinylbenzoic acid or its salt (B): Azo polymerization initiator

[0013] Furthermore, the present invention provides a method for producing modified regenerated collagen fibers, which includes a step of treating the regenerated collagen fibers by the above-described regenerated collagen fiber treatment method.

[0014] Furthermore, the present invention provides a method for manufacturing a head ornament product, which includes a step of processing regenerated collagen fibers using the above-described method for processing regenerated collagen fibers.

[0015] Furthermore, the present invention provides a headdress product containing the above-mentioned modified regenerated collagen fiber as a component.

Advantages of the Invention

[0016] According to the present invention, the water resistance and heat resistance, which are problems of regenerated collagen fibers, are improved, heat shape memory ability is imparted, stretchability (toughness) and surface feel are improved, and furthermore, modified regenerated collagen fibers without coloring can be provided.

Modes for Carrying Out the Invention

[0017] 〔Fibers to be Treated in the Present Invention〕 The fibers to be treated in the fiber treatment of the present invention are fibers artificially produced using collagen-derived polymers or oligomers as raw materials, that is, regenerated collagen fibers using collagen as a raw material.

[0018] Regenerated collagen fibers can be produced by known techniques, and the composition does not necessarily have to be 100% collagen, and natural or synthetic polymers or additives for quality improvement may be included. Furthermore, it may be a post-processed product of regenerated collagen fibers. As the form of regenerated collagen fibers, filaments are preferred. Filaments are generally taken out from those wound on a bobbin or in a boxed state. Also, the filaments coming out of the drying process in the manufacturing process of regenerated collagen fibers can be directly used.

[0019] For the raw material of collagen used in the production of regenerated collagen fibers, it is preferable to use the floor leather part. The floor leather is obtained from, for example, fresh floor leather obtained by slaughtering livestock animals such as cows or salted raw hides. These floor leathers, etc., are mostly composed of insoluble collagen fibers, but are usually used after removing the fleshy parts adhering in a net-like manner and removing the salt content used for preventing spoilage and deterioration.

[0020] These insoluble collagen fibers contain impurities such as lipids such as glycerides, phospholipids, and free fatty acids, proteins other than collagen such as glycoproteins and albumin, etc. These impurities have a great impact on spinning stability, quality such as luster and strength elongation, odor, etc. during fiber formation. Therefore, for example, after pickling to hydrolyze the fat content in the insoluble collagen fibers and loosen the collagen fibers, it is preferable to perform conventional leather treatments such as acid / alkali treatment, enzyme treatment, and solvent treatment in advance to remove these impurities.

[0021] The insoluble collagen subjected to the above-mentioned treatment is solubilized in order to cut the cross-linked peptide part. As a method of such solubilization treatment, generally adopted known alkali solubilization methods, enzyme solubilization methods, etc. can be applied. Furthermore, the alkali solubilization method and the enzyme solubilization method may be used in combination.

[0022] When applying the alkali solubilization method, it is preferable to neutralize with an acid such as hydrochloric acid. In addition, as an improved method of the conventionally known alkali solubilization method, the method described in Japanese Patent Publication No. 46-15033 may be used.

[0023] The enzyme solubilization method has the advantage of being able to obtain solubilized collagen with a uniform molecular weight, and is a method that can be preferably adopted in the present invention. As such an enzyme solubilization method, for example, the methods described in Japanese Patent Publication No. 43-25829, Japanese Patent Publication No. 43-27513, etc. can be adopted.

[0024] When the collagen subjected to the solubilization treatment as described above is further subjected to operations such as pH adjustment, salting out, water washing, solvent treatment, etc., it is possible to obtain regenerated collagen fibers excellent in quality, etc., so it is preferable to perform these treatments.

[0025] The obtained solubilized collagen is dissolved in an acid such as hydrochloric acid, acetic acid, or lactic acid to adjust the collagen aqueous solution to have a pH of 2 to 4.5 and a collagen concentration of 1% by mass or more, preferably 2% by mass or more, and 15% by mass or less, preferably 10% by mass or less. The collagen aqueous solution may be degassed under reduced pressure stirring as needed, or filtered to remove fine debris that is insoluble in water. Furthermore, the collagen aqueous solution may be further mixed with appropriate amounts of additives such as stabilizers and water-soluble polymer compounds as needed, for purposes such as improving mechanical strength, water and heat resistance, gloss, spinnability, preventing discoloration, and preservation.

[0026] The collagen aqueous solution is extruded, for example, through a spinning nozzle or slit, and immersed in an inorganic salt aqueous solution to form regenerated collagen fibers. As the inorganic salt aqueous solution, for example, an aqueous solution of a water-soluble inorganic salt such as sodium sulfate, sodium chloride, or ammonium sulfate is used. Typically, the concentration of the inorganic salt in these inorganic salt aqueous solutions is adjusted to 10 to 40% by mass. The pH of the inorganic salt aqueous solution is preferably 2 or higher, more preferably 4 or higher, preferably 13 or lower, and more preferably 12 or lower. For adjusting this pH, for example, metal salts such as sodium borate or sodium acetate, hydrochloric acid, boric acid, acetic acid, or sodium hydroxide can be used. When the pH of the inorganic salt aqueous solution is within the above range, the peptide bonds of collagen are less susceptible to hydrolysis, making it easier to obtain the desired fibers. The temperature of the inorganic salt aqueous solution is not particularly limited, but it is usually desirable to keep it below 35°C because it prevents denaturation of soluble collagen, does not reduce the strength of the spun fibers, and facilitates the production of stable yarn. The lower limit of the temperature of the inorganic salt aqueous solution is not particularly limited, but it can usually be adjusted appropriately according to the solubility of the inorganic salt.

[0027] The regenerated collagen fibers may be pre-treated (crosslinked) by immersing them in an epoxy compound or a solution thereof. The amount of epoxy compound is preferably 0.1 equivalents or more, more preferably 0.5 equivalents or more, even more preferably 1 equivalent or more, and preferably 500 equivalents or less, more preferably 100 equivalents or less, and even more preferably 50 equivalents or less, relative to the amount of amino groups in the regenerated collagen fibers that can react with the epoxy compound, as measured by amino acid analysis. The amount of epoxy compound being within the above range is preferable in terms of industrial handling and environmental friendliness, as it sufficiently imparts a water-insolubilizing effect to the regenerated collagen fibers.

[0028] Epoxy compounds can be used as is or dissolved in various solvents. Examples of solvents include water; alcohols such as methyl alcohol, ethyl alcohol, and isopropanol; ethers such as tetrahydrofuran and dioxane; halogenated organic solvents such as dichloromethane, chloroform, and carbon tetrachloride; and neutral organic solvents such as dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). These solvents may be used individually or in mixtures of two or more. When water is used as a solvent, aqueous solutions of inorganic salts such as sodium sulfate, sodium chloride, and ammonium sulfate may be used as needed. Typically, the concentration of the inorganic salt in the aqueous solution is adjusted to 10-40% by mass. The pH of the aqueous solution may also be adjusted using metal salts such as sodium borate and sodium acetate, or hydrochloric acid, boric acid, acetic acid, or sodium hydroxide. In this case, the pH of the aqueous solution is preferably 6 or higher, more preferably 8 or higher, from the viewpoint of ensuring that the reaction between the epoxy group of the epoxy compound and the amino group of collagen is not slowed down and that insolubilization in water is sufficient. Furthermore, since the pH of aqueous solutions of inorganic salts tends to decrease over time, a buffer may be used if necessary.

[0029] From the viewpoint of preventing the regenerated collagen fibers from denature, maintaining the strength of the resulting fibers, and facilitating the stable production of yarn, the treatment temperature of the regenerated collagen fibers with the epoxy compound is preferably 50°C or lower.

[0030] The regenerated collagen fibers may then be washed, oiled, and dried. Washing can be done, for example, by running water for 10 minutes to 4 hours. As the oiling agent, for example, an emulsion of amino-modified silicone, epoxy-modified silicone, polyether-modified silicone, and a Pluronic-type polyether-based antistatic agent can be used. The drying temperature is preferably 100°C or lower, more preferably 75°C or lower.

[0031] From the viewpoint of improving water resistance, the regenerated collagen fibers to be treated are preferably those containing polyvalent metals, their salts, or complexes. Examples of polyvalent metals include calcium, magnesium, strontium, barium, zinc, chromium, aluminum, titanium, zirconium, tin, lead, antimony, iron, and copper. From the viewpoint of improving water resistance, reducing discoloration of the fibers, reducing environmental impact, and improving economic efficiency, aluminum, zirconium, and titanium are preferably used, and aluminum is more preferably used. From the viewpoint of improving water resistance, the content of polyvalent metals, their salts, or complexes in the regenerated collagen fibers is preferably 1.0% by mass or more, more preferably 2.0% by mass or more, even more preferably 3.0% by mass or more, and even more preferably 5.0% by mass or more, as a metal element amount. Furthermore, from the viewpoint of improving the feel of the fiber surface, it is preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, and even more preferably 10% by mass or less. In other words, the content of polyvalent metals, or their salts or complexes, in the regenerated collagen fibers to be processed is, from the above viewpoint, preferably 1.0 to 40% by mass, more preferably 2.0 to 30% by mass, even more preferably 3.0 to 20% by mass, and even more preferably 5.0 to 10% by mass, as the amount of metal elements.

[0032] [Fiber processing method] (Single-stage processing vs. multi-stage processing) The fiber treatment method of the present invention includes both a one-step treatment using a single-component fiber treatment agent consisting of a single composition, and a multi-step treatment using a multi-component fiber treatment agent consisting of multiple compositions, such as a two-component system, in which regenerated collagen fibers are sequentially immersed in these multiple compositions. The single-component fiber treatment agent also includes those in which multiple compositions are mixed at the time of use to form a single composition. In the present invention, the content in the fiber treatment agent refers to the content in a single composition constituting a one-component fiber treatment agent in the case of a one-stage treatment, and refers to the content in each treatment agent used in each stage in the case of a multi-stage treatment.

[0033] (Basic procedures) The fiber processing method of the present invention includes the following step (i), which improves the water resistance and heat resistance, which are problems of regenerated collagen fibers, imparts thermal shape memory ability, and improves elasticity (toughness) and surface feel, and moreover, provides modified regenerated collagen fibers that are free of discoloration. Step (i) A step of immersing regenerated collagen fibers in a fiber treatment agent consisting of a single composition or a multi-component fiber treatment agent consisting of multiple compositions, the fiber treatment agent containing the following components (A) and (B) in its total composition. (A): Vinylbenzoic acid or its salt (B): Azo polymerization initiator

[0034] Examples of multi-component fiber treatment agents include a two-component fiber treatment agent comprising a first agent containing component (A) and a second agent containing component (B). When using such a multi-component fiber treatment agent, step (i) is a multi-stage treatment process in which regenerated collagen fibers are sequentially immersed in each agent. For example, when using the aforementioned two-component fiber treatment agent, step (i) is a two-stage treatment process in which regenerated collagen fibers are immersed in the first agent containing component (A), and then immersed in the second agent containing component (B), after which the regenerated collagen fibers have been treated with the first agent, or a two-stage treatment process in which regenerated collagen fibers are immersed in the second agent containing component (B), and then immersed in the first agent containing component (A), after which the regenerated collagen fibers have been treated with the second agent.

[0035] Component (A) is vinylbenzoic acid or a salt thereof. Examples of vinylbenzoic acid include 2-vinylbenzoic acid, 3-vinylbenzoic acid, 4-vinylbenzoic acid, and mixtures of two or three selected from these, but a mixture of three is preferred from the viewpoint of availability and good surface feel of the treated fibers. On the other hand, 4-vinylbenzoic acid is preferred from the viewpoint of imparting water resistance. Examples of components (A) being salts include alkali metal salts such as sodium salts and potassium salts.

[0036] The content of component (A) in the fiber treatment agent varies depending on the pH range of the fiber treatment agent, but the range shown below is preferred. Note that if the fiber treatment agent is a multi-component, multi-stage treatment, "content of component (A)" here refers to the content in the composition containing component (A), and "pH of the fiber treatment agent" here refers to the pH of the treatment agent containing component (A). If there are multiple treatment agents containing component (A), the preferred content range is determined according to the pH of each treatment agent. Note that, as mentioned above, a single composition obtained by mixing multiple compositions at the time of use is included in the single-component fiber treatment agent category, and "pH of the fiber treatment agent" refers to the pH after mixing.

[0037] When the pH of the fiber treatment agent is 2.0 or higher and less than 6.5, from the viewpoint of imparting high shape retention, water resistance, elasticity (toughness, i.e., high elongation at break when the fiber is tensile) and heat resistance to the modified and regenerated collagen fibers after treatment, the content of component (A) in the fiber treatment agent is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, even more preferably 0.5% by mass or more, and even more preferably 1.0% by mass or more, in terms of vinyl benzoic acid monomer. Furthermore, from the viewpoint of improving the feel of the fiber surface, it is preferably 30% by mass or less, more preferably 25% by mass or less, even more preferably 20% by mass or less, and even more preferably 15% by mass or less. In other words, when the pH of the fiber treatment agent is 2.0 or higher and less than 6.5, the content of component (A) in the fiber treatment agent is, from the above viewpoint, preferably 0.1 to 30% by mass, more preferably 0.2 to 25% by mass, even more preferably 0.5 to 20% by mass, and even more preferably 1.0 to 15% by mass, when converted to vinyl benzoic acid monomer.

[0038] When the pH of the fiber treatment agent is 6.5 or higher and 11.0 or lower, from the viewpoint of imparting high shape retention, water resistance, elasticity (toughness, i.e., high elongation at break when the fiber is tensile) and heat resistance to the modified and regenerated collagen fibers after treatment, the content of component (A) in the fiber treatment agent is preferably 1.0% by mass or more, more preferably 2.0% by mass or more, even more preferably 5.0% by mass or more, and even more preferably 10% by mass or more, in terms of vinyl benzoic acid monomer. Furthermore, from the viewpoint of improving the feel of the fiber surface, it is preferably 90% by mass or less, more preferably 80% by mass or less, even more preferably 70% by mass or less, and even more preferably 60% by mass or less. In other words, when the pH of the fiber treatment agent is 6.5 or higher and 11.0 or lower, the content of component (A) in the fiber treatment agent is, from the above viewpoint, preferably 1.0 to 90% by mass, more preferably 2.0 to 80% by mass, even more preferably 5.0 to 70% by mass, and even more preferably 10 to 60% by mass, when converted to vinyl benzoic acid monomer.

[0039] Component (B) is an azo polymerization initiator for polymerizing component (A). Component (B) may be included in the same composition as component (A), or the fiber treatment agent used may be a multi-component, for example, a two-component, and component (B) may be included in a composition (second component) separate from the composition (first component) containing component (A).

[0040] Examples of azo polymerization initiators include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitride), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile), dimethyl-2,2'-azobis(2-methylpropionate), 2,2'-azobis(2-hydroxymethylpropionitrile), 2, Examples include 2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide], 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis[2-(2-imidazolin-2-yl)propane], 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine], 2,2'-azobis(2-methylpropionamidine) dihydrochloride, and 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride.

[0041] For hydrophilic regenerated collagen fibers, the fiber treatment agent is preferably an aqueous solution from the viewpoint of promoting the penetration of compounds in the solution into the fibers. Therefore, the azo polymerization initiator to be incorporated into the fiber treatment agent is also preferably water-soluble. Preferred water-soluble azo polymerization initiators include 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide], 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis[2-(2-imidazolin-2-yl)propane], 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine], 2,2'-azobis(2-methylpropionamidine) dihydrochloride, and 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride.

[0042] Here, a water-soluble azo polymerization initiator refers to an azo polymerization initiator that corresponds to the following terms indicating the degree of solubility, which are defined by the volume of water (mL) required to dissolve 1 g of azo polymerization initiator powder in water when it is placed in water and shaken vigorously for 30 seconds every 5 minutes at 20°C ± 5°C, preferably "slightly soluble" to "very soluble", more preferably "slightly soluble" to "very soluble", even more preferably "slightly soluble" to "very soluble", even more preferably "easy to dissolve" to "very soluble", and even more preferably "very soluble".

[0043] <Amount of water required to dissolve 1g of azo polymerization initiator> Extremely soluble: less than 1 mL Easily soluble: 1 mL to less than 10 mL Slightly soluble: 10mL or more and less than 30mL Slightly difficult to dissolve: 30mL to less than 100mL Poorly soluble: 100mL or more but less than 1000mL Extremely poorly soluble: 1000 mL or more, less than 10000 mL Almost insoluble: 10,000 mL or more

[0044] Furthermore, as a treatment agent for regenerated collagen fibers with low heat resistance, it is more preferable to use an azo polymerization initiator with a low 10-hour half-life temperature that efficiently cleaves even at low treatment temperatures and functions as a radical initiator. Among these, 2,2'-azobis[2-(2-imidazolin-2-yl)propane] (10-hour half-life temperature: 61°C), 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine] (10-hour half-life temperature: 57°C), 2,2'-azobis(2-methylpropionamidine) dihydrochloride (10-hour half-life temperature: 56°C), and 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride (10-hour half-life temperature: 44°C) are preferred.

[0045] Here, the 10-hour half-life temperature of the azo polymerization initiator refers to the temperature at which 50% of the azo polymerization initiator decomposes after 10 hours. From the viewpoint of efficiently promoting the reaction at low temperatures without damaging the regenerated collagen fibers, which are sensitive to high temperatures, the 10-hour half-life temperature of the azo polymerization initiator is preferably 80°C or lower, more preferably 70°C or lower, even more preferably 60°C or lower, and even more preferably 50°C or lower. Furthermore, from the viewpoint of not exhibiting excessive reactivity during storage at room temperature and being advantageous for storage and transportation, it is preferably 0°C or higher, more preferably 10°C or higher, and even more preferably 20°C or higher.

[0046] Component (B) can be used alone or in combination of two or more types. The content of component (B) in the fiber treatment agent is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, even more preferably 0.1% by mass or more, and even more preferably 0.5% by mass or more, when converted to the non-dissociated form in the case of salts or complexes, from the viewpoint of efficiently carrying out the reaction and imparting high shape retention, water resistance, elasticity (toughness, i.e., high elongation at break when the fiber is tensile), water resistance, elasticity (toughness, i.e., high elongation at break when the fiber is tensile), and heat resistance to the modified and regenerated collagen fibers after treatment. Furthermore, from the viewpoint of preventing the molecular weight of the polymer produced from becoming too small due to excessive concentration, it is preferably 80% by mass or less, more preferably 60% by mass or less, even more preferably 40% by mass or less, and even more preferably 20% by mass or less. In the case of fiber treatment agents, when the fiber treatment agent is a multi-component, multi-stage treatment, "content of component (B)" as used herein refers to the content in the composition containing component (B).

[0047] The mass ratio (B) / (A) of component (B) to component (A) in the fiber treatment agent is preferably 0.001 or higher, more preferably 0.01 or higher, and also preferably 200 or lower, more preferably 50 or lower, from the viewpoint of efficiently carrying out the reaction and imparting high shape retention, water resistance, elasticity (toughness, i.e., high elongation at break when the fiber is tensile) and heat resistance to the modified and regenerated collagen fibers after treatment. In the case of a multi-component fiber treatment agent in which component (A) and component (B) are contained in separate treatment agents, it is sufficient that the mass ratio (B) / (A) in the mixed solution obtained by virtually mixing the two agents is within the above range.

[0048] The fiber treatment agent used in step (i) uses water as a medium. The water content in the fiber treatment agent is preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, even more preferably 40% by mass or more, and also preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less. In other words, the water content in the fiber treatment agent is preferably 10 to 95% by mass, more preferably 20 to 90% by mass, even more preferably 30 to 85% by mass, and even more preferably 40 to 85% by mass.

[0049] The pH of the fiber treatment agent used in step (i) is preferably 2.0 or higher, more preferably 3.0 or higher, even more preferably 3.5 or higher, even more preferably 4.0 or higher, and also preferably 11.0 or lower, more preferably 10.0 or lower, and even more preferably 9.0 or lower, from the viewpoint of suppressing damage to regenerated collagen fibers and improving durability. Note that the pH values ​​in this invention are those at 25°C. In other words, the pH of the fiber treatment agent is preferably 2.0 to 11.0, more preferably 3.0 to 10.0, even more preferably 3.5 to 9.0, and even more preferably 4.0 to 9.0, from the viewpoint of suppressing damage to regenerated collagen fibers and improving their durability. In the case of multi-component fiber treatment agents, the above conditions apply to the pH of each agent. However, it is preferable that the pH of each agent be close; specifically, the difference in pH between the agent with the highest pH and the agent with the lowest pH is preferably 3.0 or less, more preferably 2.0 or less, even more preferably 1.0 or less, and even more preferably 0.5 or less. As mentioned above, a single composition made by mixing multiple compositions at the time of use is included in the single-component fiber treatment agent category, and "pH of the fiber treatment agent" refers to the pH after mixing.

[0050] In step (i), the regenerated collagen fibers to be subjected to fiber treatment may be dry or wet. For example, they may be treated directly in the state before drying during the production of the regenerated collagen fibers. The amount of fiber treatment agent used to immerse the regenerated collagen fibers is preferably 2.0 or more, more preferably 3.0 or more, even more preferably 5.0 or more, even more preferably 10 or more, even more preferably 20 or more, and also preferably 500 or less, more preferably 250 or less, and even more preferably 100 or less, in terms of the bath ratio (mass of fiber treatment agent / mass of regenerated collagen fibers) to the mass of the regenerated collagen fibers. In other words, the bath ratio is preferably 2.0 to 500, more preferably 3.0 to 250, even more preferably 5.0 to 100, even more preferably 10 to 100, and even more preferably 20 to 100.

[0051] Furthermore, in step (i), the regenerated collagen fibers may be fixed in advance with a curler or the like, and then subjected to the fiber treatment of the present invention under heating. By doing so, the regenerated collagen fibers can be given thermal shape memory ability, high durability, and the desired shape simultaneously.

[0052] In step (i), the immersion of regenerated collagen fibers into the fiber treatment agent is preferably carried out under heating, and this heating is performed by warming the fiber treatment agent. This heating may be carried out by immersing the regenerated collagen fibers in the heated fiber treatment agent, or by immersing the regenerated collagen fibers in a low-temperature fiber treatment agent and then heating it. The temperature of the fiber treatment agent is preferably 20°C or higher, more preferably 35°C or higher, and even more preferably 45°C or higher, in order to obtain the effects of the present invention by increasing the interaction between component (A) or polymers containing component (A) as constituent monomers and fiber constituent molecules in the regenerated collagen fibers, such as protein molecules. Furthermore, in order to prevent the regenerated collagen fibers from denature and degrading due to heat, the temperature is preferably less than 100°C, more preferably 80°C or lower, even more preferably 70°C or lower, and even more preferably 60°C or lower.

[0053] The immersion time in step (i) is adjusted as appropriate depending on the heating temperature, but for example, from the viewpoint of exhibiting an effect of improving the elasticity of the regenerated collagen fibers, it is preferably 15 minutes or more, more preferably 30 minutes or more, and even more preferably 1 hour or more, and in order to suppress damage to the regenerated collagen fibers, it is preferably 48 hours or less, more preferably 24 hours or less, and even more preferably 12 hours or less.

[0054] Step (i) is preferably carried out in an environment in which the evaporation of moisture is suppressed. Specific means of suppressing the evaporation of moisture include covering the container of the fiber treatment agent in which the regenerated collagen fibers are immersed with a film-like substance, cap, lid, etc., made of a material that does not allow water vapor to pass through.

[0055] In the case of multi-stage processing using a multi-component fiber treatment agent, the aforementioned bath ratio, temperature, immersion time, and other conditions are applied at each stage. In addition, rinsing, drying, etc. may be performed between stages in the case of multi-stage processing.

[0056] After step (i), the regenerated collagen fibers may be rinsed, or they may not be rinsed. However, rinsing is preferable from the viewpoint of preventing a decrease in the feel of the surface of the regenerated collagen fibers due to excess component (A) or polymers containing component (A) as constituent monomers.

[0057] The processing in step (i) is thought to cause various effects by allowing components (A) and (B) to penetrate the regenerated collagen fibers, polymerizing component (A) as a constituent monomer, and strongly coordinating with metals, such as polyvalent metals, within the fibers. In other words, the regenerated collagen fiber processing method including step (i) can produce modified regenerated collagen fibers containing component (A) within the fibers. The resulting modified regenerated collagen fibers can be shaped by heat setting, and exhibit excellent water resistance, heat resistance, and tensile modulus, resulting in fibers with significantly improved elasticity (toughness) compared to regenerated collagen fibers.

[0058] [Modified and regenerated collagen fiber] The modified regenerated collagen fibers of the present invention obtained by the above method will be described below.

[0059] (Component (A): Vinylbenzoic acid or its salt) The modified regenerated collagen fiber of the present invention contains vinylbenzoic acid or a salt thereof as component (A), or a polymer containing component (A) as a constituent monomer. Examples of vinylbenzoic acid include 2-vinylbenzoic acid, 3-vinylbenzoic acid, 4-vinylbenzoic acid, and mixtures of two or three selected from these, but a mixture of three is preferred from the viewpoint of availability and good surface feel of the fiber after treatment. On the other hand, 4-vinylbenzoic acid is preferred from the viewpoint of water resistance. Examples of cases where component (A) is a salt include alkali metal salts such as sodium salts and potassium salts.

[0060] From the viewpoint of having higher shape retention, water resistance and heat resistance, the content of component (A) and polymers containing component (A) as constituent monomers in the modified regenerated collagen fibers of the present invention is preferably 1.0% by mass or more, more preferably 5.0% by mass or more, even more preferably 10% by mass or more, even more preferably 15% by mass or more, and even more preferably 20% by mass or more, when converted to vinyl benzoic acid monomer. Furthermore, from the viewpoint of improving the feel of the fiber surface, it is preferably 70% by mass or less, more preferably 60% by mass or less, even more preferably 50% by mass or less, and even more preferably 40% by mass or less.

[0061] In other words, the content of component (A) and polymers containing component (A) as constituent monomers in the modified regenerated collagen fibers of the present invention is, from the above viewpoint, preferably 1.0 to 70% by mass, more preferably 5.0 to 60% by mass, even more preferably 10 to 50% by mass, even more preferably 15 to 40% by mass, and even more preferably 20 to 40% by mass, when converted to vinyl benzoic acid monomer.

[0062] (Component (C): Polyvalent metal, or its salt or complex) The modified regenerated collagen fibers of the present invention preferably contain (C) a polyvalent metal, or a salt or complex thereof, from the viewpoint of improving water resistance. Examples of polyvalent metals include calcium, magnesium, strontium, barium, zinc, chromium, aluminum, titanium, zirconium, tin, lead, antimony, iron, and copper. From the viewpoint of improving water resistance, reducing discoloration of the fibers, reducing environmental impact, and improving economic efficiency, aluminum, zirconium, and titanium are preferably used, and aluminum is more preferably used. Any of these can be used individually or in combination of two or more.

[0063] From the viewpoint of improving water resistance, the content of component (C) in the modified regenerated collagen fiber of the present invention is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1.0% by mass or more, and even more preferably 2.0% by mass or more, as a metal element amount. Furthermore, from the viewpoint of improving the feel of the fiber surface, it is preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, and even more preferably 10% by mass or less. In other words, from the above viewpoint, the content of component (C) in the modified regenerated collagen fiber of the present invention is preferably 0.1 to 40% by mass, more preferably 0.5 to 30% by mass, even more preferably 1.0 to 20% by mass, and even more preferably 2.0 to 10% by mass, as a metal element amount.

[0064] The modified regenerated collagen fiber of the present invention can be shaped by heat setting, has excellent water resistance, heat resistance, and tensile modulus, and is a fiber that greatly improves the elasticity (toughness) of regenerated collagen fiber. Therefore, the modified regenerated collagen fiber of the present invention can be suitably used as a fiber for headwear products, and various headwear products can be manufactured using this fiber. Suitable headwear products in this invention include, for example, hair wigs, hairpieces, weaving, hair extensions, braided hair, hair accessories, doll hair, and the like.

[0065] The modified regenerated collagen fiber of the present invention may be used alone as a headwear product, or it may be mixed with other fibers to form a headwear product. The other fibers can be any fiber that can be used in a headwear product, and are not particularly limited. Examples of other fibers include polyester fibers, human hair, animal hair, polyvinyl chloride fibers, modacrylic fibers, polyamide fibers, polyolefin fibers, etc. Among these, polyester fibers are preferred from the viewpoint of excellent heat resistance, flame retardancy, and curl retention, and flame-retardant polyester fibers are more preferred.

[0066] The flame-retardant polyester fiber is not particularly limited, but from the viewpoint of flame retardancy, it is preferable to include 5 to 40 parts by mass of a brominated epoxy flame retardant per 100 parts by mass of one or more polyester resins selected from the group consisting of polyalkylene terephthalate and copolymer polyesters mainly composed of polyalkylene terephthalate. In the present invention, "mainly composed of" means that it is contained in an amount of 50 mol% or more, and "copolymer polyester mainly composed of polyalkylene terephthalate" means a copolymer polyester containing 50 mol% or more of polyalkylene terephthalate. Preferably, the "copolymer polyester mainly composed of polyalkylene terephthalate" contains 60 mol% or more of polyalkylene terephthalate, more preferably 70 mol% or more, and even more preferably 80 mol% or more. The flame-retardant polyester fiber is further preferably composed of 0 to 5 parts by mass of an antimony compound per 100 parts by mass of polyester resin. The inclusion of an antimony compound improves the flame retardancy of the polyester fiber.

[0067] With respect to the embodiments described above, preferred embodiments of the present invention are further disclosed below.

[0068] <1> Modified regenerated collagen fiber comprising the following component (A) or a polymer containing component (A) as a constituent monomer in the regenerated collagen fiber. (A) Vinylbenzoic acid or its salt

[0069] <2> The content of component (A), when converted to vinyl benzoic acid monomer, is preferably 1.0% by mass or more, more preferably 5.0% by mass or more, even more preferably 10% by mass or more, even more preferably 15% by mass or more, even more preferably 20% by mass or more, and also preferably 70% by mass or less, more preferably 60% by mass or less, even more preferably 50% by mass or less, and even more preferably 40% by mass or less. <1> Modified and regenerated collagen fibers as described above.

[0070] <3> Preferably, it further contains the following component (C) <1> or <2> Modified and regenerated collagen fibers as described above. (C) Polyvalent metals, or their salts or complexes

[0071] <4> Component (C) is preferably one or more polyvalent metals selected from calcium, magnesium, strontium, barium, zinc, chromium, aluminum, titanium, zirconium, tin, lead, antimony, iron, and copper, or their salts or complexes; more preferably one or more polyvalent metals selected from aluminum, zirconium, and titanium, or their salts or complexes; even more preferably aluminum or its salts or complexes. <3> Modified and regenerated collagen fibers as described above.

[0072] <5> The content of component (C) is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1.0% by mass or more, even more preferably 2.0% by mass or more, and also preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, and even more preferably 10% by mass or less. <3> or <4> Modified and regenerated collagen fibers as described above.

[0073] <6> A method for processing regenerated collagen fibers, including the following step (i). Step (i) A step of immersing regenerated collagen fibers in a fiber treatment agent consisting of a single composition or a multi-component fiber treatment agent consisting of multiple compositions, the fiber treatment agent containing the following components (A) and (B) in its total composition. (A): Vinylbenzoic acid or its salt (B): Azo polymerization initiator

[0074] <7> The fiber treatment agent in step (i) is a multi-component fiber treatment agent comprising a first agent containing component (A) and a second agent containing component (B), Step (i) includes a step of immersing regenerated collagen fibers in a first agent, then immersing the regenerated collagen fibers after treatment with the first agent in a second agent, or a step of immersing regenerated collagen fibers in a second agent, then immersing the regenerated collagen fibers after treatment with the second agent in a first agent. <6> The method for processing regenerated collagen fibers as described above.

[0075] <8> Prior to step (i), the process includes a step for producing regenerated collagen fibers, in which an aqueous solution of solubilized collagen obtained by solubilizing insoluble collagen fibers made from the hides of livestock animals is extruded through a spinning nozzle or slit and immersed in an aqueous solution of inorganic salts. <6> or <7> The method for processing regenerated collagen fibers as described above.

[0076] <9> Preferably, after the regenerated collagen fiber manufacturing step, the process includes a crosslinking step in which the regenerated collagen fiber is immersed in an epoxy compound or a solution thereof. <8> The method for processing regenerated collagen fibers as described above.

[0077] <10> Component (B) is preferably a water-soluble azo polymerization initiator, and more preferably one or more selected from 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide], 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis[2-(2-imidazolin-2-yl)propane], 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine], 2,2'-azobis(2-methylpropionamidine) dihydrochloride, and 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride. <6> ~ <9> A method for processing regenerated collagen fibers as described in any one of the items.

[0078] <11> The content of component (B) in the fiber treatment agent (or, in the case of a multi-component fiber treatment agent, the content of component (B) in the composition containing component (B)) is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, even more preferably 0.1% by mass or more, even more preferably 0.5% by mass or more, and also preferably 80% by mass or less, more preferably 60% by mass or less, even more preferably 40% by mass or less, and even more preferably 20% by mass or less. <6> ~ <10> A method for processing regenerated collagen fibers as described in any one of the items.

[0079] <12> The regenerated collagen fiber contains the following component (C): <6> ~ <11> A method for processing regenerated collagen fibers as described in any one of the items. (C) Polyvalent metals, or their salts or complexes

[0080] <13> Component (C) is preferably one or more polyvalent metals selected from calcium, magnesium, strontium, barium, zinc, chromium, aluminum, titanium, zirconium, tin, lead, antimony, iron, and copper, or their salts or complexes; more preferably one or more polyvalent metals selected from aluminum, zirconium, and titanium, or their salts or complexes; even more preferably aluminum or its salts or complexes. <12> The method for processing regenerated collagen fibers as described above.

[0081] <14> The pH of the fiber treatment agent used in step (i) at 25°C is preferably 2.0 or higher, more preferably 3.0 or higher, even more preferably 3.5 or higher, even more preferably 4.0 or higher, and also preferably 11.0 or lower, more preferably 10.0 or lower, and even more preferably 9.0 or lower. <6> ~ <13> A method for processing regenerated collagen fibers as described in any one of the items.

[0082] <15> The pH of the treatment agent containing component (A) used in step (i) is 2.0 or higher and less than 6.5, and the content of component (A) in the treatment agent is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, even more preferably 0.5% by mass or more, even more preferably 1.0% by mass or more, and also preferably 30% by mass or less, more preferably 25% by mass or less, even more preferably 20% by mass or less, and even more preferably 15% by mass or less. <6> ~ <14> A method for processing regenerated collagen fibers as described in any one of the items.

[0083] <16> The pH of the treatment agent containing component (A) used in step (i) is 6.5 or higher and 11.0 or lower, and the content of component (A) in the treatment agent is preferably 1.0% by mass or more, more preferably 2.0% by mass or more, even more preferably 5.0% by mass or more, even more preferably 10% by mass or more, and also preferably 90% by mass or less, more preferably 80% by mass or less, even more preferably 70% by mass or less, and even more preferably 60% by mass or less. <6> ~ <14> A method for processing regenerated collagen fibers as described in any one of the items.

[0084] <17> In the fiber treatment agent (in the case of a multi-component fiber treatment agent, where component (A) and component (B) are contained in separate treatment agents, in the mixed solution obtained by virtually mixing the two agents), the mass ratio (B) / (A) of component (B) to component (A) is preferably 0.001 or more, more preferably 0.01 or more, and also preferably 200 or less, more preferably 50 or less. <6> ~ <16> A method for processing regenerated collagen fibers as described in any one of the items.

[0085] <18> The fiber treatment agent used in step (i) is water-based, and the water content in the fiber treatment agent is preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, even more preferably 40% by mass or more, and also preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less. <6> ~ <17> A method for processing regenerated collagen fibers as described in any one of the items.

[0086] <19> In step (i), the amount of fiber treatment agent used to immerse the regenerated collagen fibers is preferably 2.0 or more, more preferably 3.0 or more, even more preferably 5.0 or more, even more preferably 10 or more, even more preferably 20 or more, and also preferably 500 or less, more preferably 250 or less, and even more preferably 100 or less, in terms of the bath ratio (mass of fiber treatment agent / mass of regenerated collagen fibers) to the mass of the regenerated collagen fibers. <6> ~ <18> A method for processing regenerated collagen fibers as described in any one of the items.

[0087] <20> The temperature of the fiber treatment agent in which the regenerated collagen fibers are immersed in step (i) is preferably 20°C or higher, more preferably 35°C or higher, even more preferably 45°C or higher, and also preferably less than 100°C, more preferably 80°C or lower, even more preferably 70°C or lower, and even more preferably 60°C or lower. <6> ~ <19> A method for processing regenerated collagen fibers as described in any one of the items.

[0088] <21> The immersion time in step (i) is preferably 15 minutes or more, more preferably 30 minutes or more, even more preferably 1 hour or more, and also preferably 48 hours or less, more preferably 24 hours or less, and even more preferably 12 hours or less. <6> ~ <20> A method for processing regenerated collagen fibers as described in any one of the items.

[0089] <22> Preferably, step (i) is carried out in an environment in which the evaporation of moisture is suppressed. <6> ~ <21> A method for processing regenerated collagen fibers as described in any one of the items.

[0090] <23> <6> ~ <22> A method for producing modified regenerated collagen fibers, comprising the step of treating regenerated collagen fibers by the regenerated collagen fiber treatment method described in any one of the items.

[0091] <24> <6> ~ <22> A method for manufacturing a head ornament product, comprising the step of treating regenerated collagen fibers by the regenerated collagen fiber treatment method described in any one of the items.

[0092] <25> <1> ~ <5> A head accessory product containing modified and regenerated collagen fibers as a component, as described in any one of the items.

[0093] <26> Choose from hair wigs, hairpieces, weaving, hair extensions, braided hair, hair accessories, and doll hair. <25> Headwear products as described above. [Examples]

[0094] Example 1, Comparative Examples 1-3 The compositions shown in Table 1 were used to treat regenerated collagen fibers according to the method described below, and various evaluations were performed. The pH of each composition was measured directly using a pH meter (HORIBA F-52) at room temperature (25°C) after preparation.

[0095] <Processing method> 1. A 22cm long bundle of 0.50g of regenerated collagen fiber (*) was immersed in a container containing the amount of fiber treatment agent shown in the bath ratio in the table. The container was then sealed and the container was immersed in a water bath at the temperature shown in the table (manufacturer: Toyo Seisakusho Co., Ltd. / model number: TBS221FA) and heated for the time shown in the table. * Kaneka Corporation's regenerated collagen fibers were purchased in the form of commercially available hair extension products, and the fibers were cut and divided into small bundles for evaluation. For this evaluation, the extension products used were those labeled as using 100% Ultima fiber, with a color count of 30 (white) and a straight shape. Furthermore, these Kaneka-manufactured regenerated collagen fibers contain aluminum, and the aluminum content, as determined by the following analytical methods, was 6.8% by mass in all cases. After drying the regenerated collagen fibers in a desiccator, 0.1 g of these fibers were placed in a solution of 5 mL of nitric acid and 15 mL of hydrochloric acid and heated to dissolve. After cooling, this solution was diluted 50 times with water, and the aluminum content in the diluted aqueous solution was measured using an atomic absorption spectrometer (Z-5300 model) manufactured by Hitachi, Ltd. 2. Remove the container containing the hair bundles from the water bath and allow them to return to room temperature. 3. Remove the hair strands from the container, rinse with 30°C running tap water for 30 seconds, lather with the evaluation shampoo for 60 seconds, rinse with 30°C running tap water for 30 seconds, lightly towel dry, and then dry the hair strands with a warm air dryer (Tescom Nobby White NB3000) while combing.

[0096] <Formula for the evaluation shampoo> Ingredients (mass%) Sodium laureth sulfate 15.5 Lauramide DEA 1.5 EDTA-2Na 0.3 Amount of phosphoric acid to adjust pH to 7 Ion-exchanged water Balance Total 100

[0097] <Increase in average elongation at break during fiber tension> As an indicator of water resistance and elasticity (toughness) when fibers are stretched, the average elongation at break, that is, the percentage of the original fiber length at which break occurs when the fiber is stretched under tension, was evaluated using the average value obtained from multiple fibers (10 fibers). The evaluation was performed using hair bundles immediately after being treated with the above <treatment method>, following the procedure below. 1. Ten fibers were cut from the base of the hair bundle. A 3cm fiber piece was taken from the middle of the base and tip of each fiber, resulting in a total of 10 3cm hair pieces. 2. The fiber samples were placed in a DIA-STRON limited "MTT690 Automatic Fiber Tensile Tester". After being left immersed in water for 30 minutes, automatic measurement was started, and the average elongation at break while the fibers were immersed in water was determined. A higher value indicates greater elasticity, superior toughness, and superior durability. According to the following formula, the average elongation at break (A%) when fibers are pulled in their untreated state (untreated; Comparative Example 1) is used as the baseline. The table shows the percentage increase (C%) in the average elongation at break (B%) of treated hair bundles compared to the untreated state, as indicated in "Percentage increase in average elongation at break [%]". C(%) = B(%) - A(%)

[0098] <Increase in average breaking load during fiber tension> As an indicator of water resistance during fiber tensile stress, the average breaking load during fiber tensile stress was used. The evaluation was performed using fiber bundles immediately after treatment using the above-described <treatment method>. Furthermore, the average value obtained when evaluating multiple fibers (10 fibers) was used as the numerical value. The evaluation was performed according to the following procedure. 1. Ten fibers were cut from the base of the hair bundle. A 3cm fiber piece was taken from the middle of the base and tip of each fiber, resulting in a total of 10 3cm hair pieces. 2. The fiber samples were placed in a DIA-STRON limited "MTT690 Automatic Fiber Tensile Testing Machine". After being left immersed in water for 30 minutes, automatic measurement was started, and the breaking load when the fiber was stretched while immersed in water was determined. A higher value indicates greater stiffness and resilience, greater resistance to stretching by external forces, and superior durability. According to the following formula, the average breaking load (W0(gf)) when the fibers were tensed in their untreated state (untreated; Comparative Example 1) was used as the baseline. The table shows the increase in the average breaking load (W1(gf)) of the treated fiber bundles from the untreated state, indicated as "Increase in average breaking load when fibers are tensed [gf]". Y(gf) = W1(gf) - W0(gf)

[0099] <Shrinkage rate when using a high-temperature iron> As an indicator of heat resistance, the shrinkage rate during high-temperature ironing was used. The evaluation was performed using hair bundles immediately after treatment using the above-described <treatment method>. Furthermore, the average value obtained when evaluating multiple fibers (5 strands) was used as the numerical value. The evaluation was performed according to the following procedure. 1. Immediately after the above processing method, five fibers were cut from the base of the hair bundle and marked. The length of these five processed fibers was measured and the average value was recorded (let's call it length L1). Next, these five marked processed fibers were bundled together with two separate bundles of unprocessed regenerated collagen fibers (totaling 1g) to create a new hair bundle (hereinafter referred to as the large hair bundle). A flat iron (manufactured by Miki Electric Industry Co., Ltd. / model number: AHI-938) set to 180°C was applied to the entire large hair bundle 10 times at a speed of 5cm / sec. 2. After the ironing process, five marked treated fibers were taken from the large bundle of hair, and the length of each of these five marked treated fibers was measured again and the average value was recorded (denoted as length L2). 3. Shrinkage rate when ironing at high temperature: S dry We defined it as = { 1 - (L2 / L1)} x 100 [%]. dry The closer the value is to 0%, the less likely it is to shrink due to dry heat, indicating superior heat resistance.

[0100] <Shrinkage rate when heated with hot water> As an indicator of water resistance and heat resistance, the shrinkage rate during hot water heating was used. The evaluation was performed using hair bundles immediately after treatment using the above-described <treatment method>. Furthermore, the average value obtained when evaluating multiple fibers (5 strands) was used as the numerical value. The evaluation was performed according to the following procedure. 1. Five fibers were cut from the base of the hair bundle, the average length of each fiber was recorded (referred to as length L1), and then the bundle was immersed in a 90°C water bath (manufacturer: Toyo Seisakusho Co., Ltd. / model number: TBS221FA) and heated for 1 minute. 2. After the heating process, five fibers were removed, lightly dried with a towel, and dried at room temperature and humidity for 30 minutes. The average length of each fiber was then recorded (denoted as length L2). 3. Shrinkage rate (S) during hot water heating wet We defined it as = { 1 - (L2 / L1)} x 100 [%]. wet The closer the value is to 0%, the less likely shrinkage due to moist heat is to occur, indicating superior heat resistance.

[0101] <Thermal shape memory ability> The thermal shape memory ability was evaluated using hair bundles immediately after being treated with the above-described processing method. If the result of "I: Shape imparting (curl)" was 5% or less, it was considered to have no effect, and no further processing or evaluation was performed. • I: Shaping (curling) 1. A 22cm long bundle of 0.5g of regenerated collagen fiber was wet with 30°C tap water for 30 seconds, then the wet bundle was wrapped around a 14mm diameter plastic rod and secured with a clip. 2. The hair bundles wrapped around the rod were immersed in a 60°C water bath (manufacturer: Toyo Seisakusho Co., Ltd. / model number: TBS221FA) and heated for 1 minute. 3. Remove the hair bundles from the water bath, immerse them in 25°C water for 1 minute, remove them from the water, and allow them to return to room temperature. 4. Remove the hair bundle from the rod, comb it through three times, and then, three minutes after taking it out of the water, take a picture of it hanging from the side.

[0102] (Evaluation Criteria) Let L0 be the length of the untreated hair bundle (22 cm) and L be the length of the treated hair bundle. The curl-up rate = hair bundle length reduction rate (I) (%), calculated according to the following formula, was defined as the curl strength. I = [(L0 - L) / L0] × 100

[0103] • II: Reshaping (Straight) 1. After detangling the hair strands evaluated in step I with a comb, a flat iron (manufactured by Miki Electric Industry Co., Ltd. / model number: AHI-938) set to 180°C was slid through them 6 times at a speed of 5 cm / sec. 2. Rinse with running tap water at 30°C for 30 seconds, lather with the evaluation shampoo for 60 seconds, rinse with running tap water at 30°C for 30 seconds, and towel dry. 3. The items were hung up and air-dried at 20°C and 65% RH for 12 hours. After combing them through, they were visually inspected from the side while still hanging.

[0104] (Evaluation Criteria) The straightening rate (ST) (%), calculated according to the following formula, is defined as the degree of straightening achieved, with the untreated hair bundle length being L0 (22 cm) and the treated hair bundle length being L. When ST = 100%, the hair bundle is completely straightened. ST = [1 - (L0 - L) / L0] × 100

[0105] • III: Reshaping (curling) 1.II The hair bundles evaluated were wet with 30°C tap water for 30 seconds, then the wet hair bundles were wrapped around a 14mm diameter plastic rod and secured with a clip. 2. The hair bundles wrapped around the rod were immersed in a 60°C water bath (manufacturer: Toyo Seisakusho Co., Ltd. / model number: TBS221FA) and heated for 1 minute. 3. Remove the hair bundles from the water bath, immerse them in 25°C water for 1 minute, remove them from the water, and allow them to return to room temperature. 4. Remove the hair bundle from the rod, comb it through three times, and then, three minutes after taking it out of the water, take a picture of it hanging from the side.

[0106] (Evaluation Criteria) Let L0 be the length of the untreated hair bundle (22 cm) and L be the length of the treated hair bundle. The curl-up rate = hair bundle length reduction rate (I) (%), calculated according to the following formula, was defined as the curl strength. I = [(L0 - L) / L0] × 100

[0107] <Good surface texture> The surface texture was evaluated using hair strands immediately after treatment using the <treatment method>. Five expert panelists evaluated the smoothness of the texture when touched by hand according to the following criteria, and the sum of the five evaluations was used as the final result. (Evaluation Criteria) 5: It has an extremely smooth texture compared to untreated fibers (Comparative Example 1). 4: It has a smoother feel compared to untreated fibers (Comparative Example 1). 3: It has a slightly smoother texture compared to the untreated fibers (Comparative Example 1). 2: The texture is the same as the untreated fiber (Comparative Example 1). 1: It is rougher and has a less pleasant feel than untreated fibers (Comparative Example 1).

[0108] <Suppression of discoloration of fibers> 1. For both the front and back of each hair strand, the color was measured near the root, mid-length, and tip using a colorimeter (Konica Minolta CR-400), and the average of the six points was used as the color value (L, a, b). 2. The degree of coloring was evaluated using ΔE*ab, with untreated hair strands of color no. 30 white (*) (Comparative Example 1) as the baseline. Color measurements were taken on the same day the treatment was performed. (*) Untreated hair bundles of color number 30 white We purchased Kaneka Corporation's regenerated collagen fibers in the form of commercially available hair extension products, cut the fibers from these products, and divided them into small bundles for evaluation. For this evaluation, we used extension products that were labeled as using 100% Ultima fiber, with a color count of 30 (white) and a straight shape. Furthermore, these Kaneka-manufactured regenerated collagen fibers contain aluminum, and the aluminum content, as determined by the aforementioned analytical method, was 6.8% by mass in all cases. ΔE*ab is calculated by taking the measurements of an untreated hair bundle with color number 30 white as (L0, a0, b0) and the measurements of a treated hair bundle as (L1, a1, b1), where (L1-L0) 2 +(a1-a0) 2+(b1-b0) 2 ] 1 / 2 The color-inhibiting effect was determined according to the following criteria, as defined by [the formula]. 5:ΔE*ab ≤ 5.0 4:5.0 < ΔE*ab ≤ 10.0 3:10.0 < ΔE*ab ≤ 15.0 2:15.0 < ΔE*ab ≤ 20.0 1:20.0< ΔE*ab

[0109] [Table 1]

[0110] Examples 2-6 The first and second formulations shown in Table 2 were used to treat regenerated collagen fibers according to the method described below, and various evaluations were performed. The pH of each composition was measured directly using a pH meter (HORIBA F-52) at room temperature (25°C) after preparing the compositions. Note that the concentrations of each component listed in the table are the concentrations in the first and second formulations, respectively.

[0111] <Processing method> 1. A 22cm long hair bundle containing 0.5g of regenerated collagen fiber (*) was immersed in a container containing the amount of the first agent in the bath ratio shown in the table. The container was then sealed and the container was immersed in a water bath at the temperature shown in the table (manufacturer: Toyo Seisakusho Co., Ltd. / model number: TBS221FA) and heated for the time shown in the table. * Kaneka Corporation's regenerated collagen fibers were purchased in the form of commercially available hair extension products, and the fibers were cut and divided into small bundles for evaluation. For this evaluation, the extension products used were those labeled as using 100% Ultima fiber, with a color count of 30 (white) and a straight shape. Furthermore, these Kaneka-manufactured regenerated collagen fibers contain aluminum, and the aluminum content, as determined by the aforementioned analytical method, was 6.8% by mass in all cases. 2. Remove the container containing the hair bundles from the water bath and allow them to return to room temperature. 3. Remove the hair strands from the container, rinse with 30°C running tap water for 30 seconds, lather with the evaluation shampoo for 60 seconds, rinse with 30°C running tap water for 30 seconds, lightly towel dry, and then dry the hair strands with a warm air dryer (Tescom Nobby White NB3000) while combing. 4. The hair bundles were immersed in a container containing the amount of the second agent corresponding to the bath ratio shown in the table, the opening of the container was sealed, and the container was immersed in a water bath at the temperature shown in the table (manufacturer: Toyo Seisakusho Co., Ltd. / model number: TBS221FA) and heated for the time shown in the table. 5. Remove the container containing the hair bundles from the water bath and allow them to return to room temperature. 6. Remove the hair strands from the container, rinse with 30°C running tap water for 30 seconds, lather with the evaluation shampoo for 60 seconds, rinse again with 30°C running tap water for 30 seconds, lightly towel dry, and then dry the hair strands with a warm air dryer (Tescom Nobby White NB3000) while combing. At this point, the hair strands remained straight.

[0112] [Table 2]

[0113] Comparative Example 4 The regenerated collagen fibers were treated using the formulation shown below, according to the <treatment method> in Example 1 and Comparative Examples 1-3. The degree of coloration of the treated hair bundles was evaluated in the same manner as described above, and a brownish-red coloration was observed (Evaluation 1). Raw material name Amount [mass%] Formaldehyde 10.0 Resorcinol 15.0 Water level pH adjuster (hydrochloric acid or sodium hydroxide) (pH adjustment amount) Total 100.0 pH (25℃): 5.5 Bath ratio: 40 Heating conditions: 50℃ 3h

[0114] Furthermore, the hair bundles processed in the above embodiments can all be used as extensions by securing them to the hair with pins or the like, and can perform adequately on a human head.

Claims

1. Modified regenerated collagen fiber comprising the following component (A) or a polymer containing component (A) as a constituent monomer in the regenerated collagen fiber. (A) Vinylbenzoic acid or its salt

2. Furthermore, the modified regenerated collagen fiber according to claim 1 contains the following component (C). (C) Polyvalent metals, or their salts or complexes

3. The modified regenerated collagen fiber according to claim 2, wherein component (C) is aluminum, or a salt thereof or a complex thereof.

4. A method for processing regenerated collagen fibers, including the following step (i). Step (i) A step of immersing regenerated collagen fibers in a fiber treatment agent, which is a one-component fiber treatment agent consisting of a single composition or a multi-component fiber treatment agent consisting of multiple compositions, the fiber treatment agent containing the following components (A) and (B) in its total composition. (A): Vinylbenzoic acid or its salt (B): Azo polymerization initiator

5. The fiber treatment agent in step (i) is a multi-component fiber treatment agent comprising a first agent containing component (A) and a second agent containing component (B), The method for treating regenerated collagen fibers according to claim 4, wherein step (i) includes a step of immersing regenerated collagen fibers in a first agent, and then immersing the regenerated collagen fibers after treatment with the first agent in a second agent, or a step of immersing regenerated collagen fibers in a second agent, and then immersing the regenerated collagen fibers after treatment with the second agent in a first agent.

6. The method for processing regenerated collagen fibers according to claim 4 or 5, wherein the regenerated collagen fibers contain the following component (C). (C) Polyvalent metals, or their salts or complexes

7. The method for processing regenerated collagen fibers according to claim 6, wherein component (C) is aluminum, or a salt thereof or a complex thereof.

8. A method for producing modified regenerated collagen fibers, comprising the step of treating regenerated collagen fibers by the regenerated collagen fiber treatment method described in claim 4 or 5.

9. A method for manufacturing a head ornament, comprising the step of treating regenerated collagen fibers by the regenerated collagen fiber treatment method described in claim 4 or 5.

10. A head ornament product comprising modified regenerated collagen fibers as a component, according to any one of claims 1 to 3.