Fiber-Treating Agent

The present invention relates to a fiber-treating agent for imparting water resistance, heat resistance and heat shape memory ability to naturally derived fibers, and preferably relates to a fiber-treating agent for naturally derived fibers used in fiber products such as headdress products such as wigs and extensions.

Unlike synthetic fibers, naturally derived fibers generally have natural texture and appearance originating from a natural material. Among naturally derived fibers, regenerated protein fibers, for example, regenerated collagen fibers, are obtained by solubilizing acid-soluble collagen or by solubilizing insoluble collagen with an alkali or an enzyme to obtain a spinning stock solution, and discharging the spinning stock solution into a coagulation bath through a spinning nozzle to form fibers.

However, naturally derived fibers generally have higher hydrophilicity and hence higher water absorption as compared to synthetic fibers, and the fibers have generally low mechanical strength when they contain a large amount of water, and in particular, regenerated protein fibers have extremely low mechanical strength. This leads to deterioration of suitability as a fiber product such that during washing, mechanical strength significantly deteriorates because of the higher water absorption, and during subsequent drying, rupture occurs.

Among naturally derived fibers, regenerated protein fibers also have the problem of low heat resistance, so that, for example, if a heat set using a hair iron or the like is performed at a temperature as high as that for human hair, shrinkage or crimping occurs, resulting in impairment of visual quality.

Further, in plastic synthetic fibers, the shape in a heat set with an iron or the like is continuously memorized even after subsequent washing (there is heat shape memory ability), whereas in naturally derived fibers, the shape in a heat set with an iron or the like is lost through subsequent one time washing (there is no heat shape memory ability). Therefore, naturally derived fibers may be inferior to conventional plastic synthetic fibers in terms of degree of freedom of shape set.

The above points are supposed to be a factor in limiting popularization of naturally derived fibers, in particular regenerated protein fibers for fiber products such as headdress products. In particular, water resistance, that is, the deterioration of the mechanical strength when it is wet has a significant impact.

On the other hand, in the field of human hair fibers which are naturally derived fibers, a method is known in which to human hair fibers having essentially no heat shape memory ability, a specific aldehyde derivative and phenolic compound are applied for newly imparting heat shape memory ability (Patent Literature 1).

The present invention provides a fiber-treating agent which is a one-part type fiber-treating agent formed of a single composition or a multiple-part type fiber-treating agent formed of a plurality of compositions, the agent comprising the following components (A) to (C) in a total composition:

Further, the present invention provides a fiber-treating agent kit comprising a composition containing the following component (A) and component (C) and a composition containing the following component (B) and component (C):

In some situations of production of fiber products such as headdress products, fibers are intensively extended, and in the technique disclosed in Patent Literature 1, there are cases where the stretchability (tenacity) of treated fibers is not sufficient. For this reason, it is required to enhance the stretchability of treated fibers for preventing rupture during extension.

Therefore, the present invention relates to a fiber-treating agent which improves water resistance and heat resistance problematic in naturally derived fibers, imparts heat shape memory ability, and also improves stretchability (tenacity) and the feel of the surfaces.

The present inventors have conducted intensive studies and as a result, found that by treating naturally derived fibers with a composition containing an aromatic compound having a vinyl group or a vinylidene group and a coordinating functional group, and a radical initiator, not only the aromatic compound penetrated into the fibers are polymerized, but also its coordinating functional group is strongly coordinated with a metal (mainly polyvalent metal) in the naturally derived fibers, so that the strength in water and heat resistance of the fibers are improved, and the leakage of the aromatic compound or a polymerized product thereof from the fibers is prevented. As a result, the present inventors have found that not only water resistance, and heat resistance in both dry state and wet state of the naturally derived fibers are improved, so that the shape can be imparted by a heat set, but also surprisingly, the stretchability (tenacity) of the naturally derived fibers is improved as compared to that before treatment, and can be enhanced to a level close to that of human hair, leading to completion of the present invention.

According to the present invention, it is possible to provide a fiber-treating agent which can improve water resistance, and heat resistance in both dry state and wet state of naturally derived fibers, can impart heat shape memory ability, and can also improve the stretchability (tenacity) and the feel of the surfaces.

The fiber-treating agent of the present invention includes a one-part type fiber-treating agent formed of a single composition, and a multiple-part type fiber-treating agent such as a two-part type fiber-treating agent which is formed of a plurality of compositions and in which fibers are sequentially immersed in the plurality of compositions. The one-part type fiber-treating agent includes one used as a single composition by mixing a plurality of compositions upon use.

In the present invention, the content in the fiber-treating agent refers to, in the case of the one-part type fiber-treating agent, the content in a single composition to be used, and in the case of the multiple-part type fiber-treating agent, the content in each treating agent to be used in each step.

Fibers to be treated with the fiber-treating agent of the present invention are preferably metal-containing fibers, preferably naturally derived metal-containing fibers or synthetic metal-containing fibers, and among them, naturally derived metal-containing fibers are preferable. The naturally derived fiber refers to fibers which are taken from a natural animal or plant, or artificially produced fibers using a polymer or an oligomer, such as protein derived from keratin, collagen, casein, soybeans, peanuts, corn, silk flocks, silk protein (for example silk fibroin) or the like or a polysaccharide, as a raw material. Among them, artificially produced fibers using a polymer or an oligomer, such as protein derived from keratin, collagen, casein, soybeans, peanuts, corn, silk flocks, silk protein (for example silk fibroin) or the like or a polysaccharide, as a raw material are preferable, regenerated protein fibers using protein derived from keratin, collagen, casein, soybean protein, peanut protein, corn protein, silk protein (for example silk fibroin) or the like as a raw material are more preferable, regenerated protein fibers such as regenerated collagen fibers made from collagen as a raw material or regenerated silk fibers made from silk fibroin as a raw material are more preferable, and regenerated collagen fibers are further more preferable.

Regenerated collagen fibers can be produced by a known technique, are not required to have a composition of collagen 100%, and may contain a natural or synthetic polymer and additives for improvement of quality. Regenerated collagen fibers are preferably in the form of filaments. Filaments are generally taken from fibers wound around a bobbin or packed in a box. It is also possible to directly use filaments coming out from a drying step in a production process of regenerated collagen fibers.

Synthetic metal-containing fibers may be metal-treated synthetic fibers. Naturally derived metal-containing fibers include those originally containing a metal such as fibers taken from a natural animal or plant. In this case, those originally containing a metal are not required to contain metal additionally, but may be treated with a metal salt, as fibers treated with an aluminum salt to achieve water resistance as described in, for example, JP-A-2003-027318, and the like.

A component (A) is an aromatic compound having one or more vinyl groups or vinylidene groups, and a coordinating functional group. The coordinating functional group in the component (A) is preferably one containing a Pearson's hard base. The Pearson's hard base refers to the Lewis bases classified into hard bases in the concept of HSAB (Hard and Soft Acids and Bases) which is introduced by Pearson (R. G. Pearson) in the 1960s, and is considered to easily react with the Lewis acids classified into hard acids.

Examples of the hard base contained in the coordinating functional group in the aromatic compound of the component (A) include functional groups corresponding to hard bases described in Application of the Principle of Hard and Soft Acids and Bases to Organic Chemistry, Ralph G. Pearson and Jon. Songstad, J. Am. Chem. Soc. 1967, 89, 8, 1827-1836, such as COO, O, COOH, OH, and NH. Among them, COO, O, COOH, and OH are preferable, and COOand COOH are more preferable from the viewpoint of further reducing coloring of fibers and improving fixability after fiber treatment (suppressing elution during washing). As the coordinating functional group in the component (A), a functional group containing a carboxy group or a group in which one hydrogen atom is eliminated from the benzene ring of catechol (1,2-dihydroxybenzene) is preferable.

Hereinafter, the aromatic compound of the component (A) will be exemplified by being divided into (A-1) the case where the coordinating functional group contains COOH, COO, or a salt of COOH, and (A-2) the case where the coordinating functional group contains OH, O, or a salt of OH.

(a-1) Case where Coordinating Functional Group Contains COOH, COO, or Salt of COOH

Examples of (A-1) include (A-1-a) an aromatic compound having a vinyl group or a vinylidene group as a part of a styrene backbone, and (A-1-b) an aromatic compound having a vinyl group or a vinylidene group as a part of an acryloyl group or a methacryloyl group. When the component (A-1) is a salt, examples of the salt include alkaline metal salts such as sodium salts and potassium salts.

(a-1-a) Case where Coordinating Functional Group Contains COOH, COO, or Salt of COOH, and Vinyl Group or Vinylidene Group is Part of Styrene Backbone

Examples of the aromatic compound of (A-1-a) include a compound of the following formula (1):

In (A-1-a), when Ato Acontain at least one carboxy group, specific examples of the aromatic compound include 2-vinylbenzoic acid, 3-vinylbenzoic acid, 4-vinylbenzoic acid, and a mixture of two or three selected from the group consisting of them, and a mixture of three is preferable from the viewpoint of easy availability and good feel quality of the surface of fibers after treatment. On the other hand, 4-vinylbenzoic acid is preferable from the viewpoint of imparting water resistance.

In (A-1-a), when Ato Acontain at least one group of formula (2), specific examples of the aromatic compound include 4-oxo-4-((4-vinylbenzyl)oxy)butanoic acid and 2-(((4-vinylbenzyl)oxy)carbonyl)benzoic acid.

(a-1-b) Case where Coordinating Functional Group Contains COOH, COO, or Salt of COOH, and Vinyl Group or Vinylidene Group is Part of Acryloyl Group or Methacryloyl Group

Examples of the aromatic compound of (A-1-b) include a compound of the following formula (3):

Specific examples of the aromatic compound of formula (3) include 2-((2-(acryloyloxy)ethoxy)carbonyl)benzoic acid, 2-((2-(methacryloyloxy)ethoxy)carbonyl)benzoic acid, and 2-(4-(2-(2-(acryloyloxy)ethoxy)ethoxy)benzoyl)benzoic acid.

(a-2) Case where Coordinating Functional Group Contains OH, O, or Salt of OH

Examples of (A-2) include a compound of the following formula (4):

Specific examples of the aromatic compound of formula (4) include 3,4,5-trihydroxybenzoic acid 4-vinylbenzyl.

The component (A) more preferably corresponds to (A-1), from the viewpoint of further reducing coloring of fibers and improving fixability after fiber treatment (suppressing elution during washing).

One component (A) may be used alone, or two or more components (A) may be used in combination. The content of the component (A) in the fiber-treating agent of the present invention is different depending on the pH range of the fiber-treating agent, and the following range is preferable. Here, the content of the component (A) in the case where the component (A) is a salt refers to the content of the corresponding undissociated form. The content of the undissociated form refers to, in the case of an acid, the content of the state where the counter ion is substituted with a hydrogen, for example, in the case of a COO-salt, the content of its acid form COOH, and in the case of a base, the content of the state where proton is eliminated, for example, in the case of an ammonium salt, the content of the state of amine. When the fiber-treating agent is a multiple-part type fiber-treating agent, “the pH of the fiber-treating agent” here refers to the pH of the treating agent containing the component (A). When there is a plurality of treating agents containing the component (A), the preferred range of the content is determined depending on the pH of each treating agent. As described above, the fiber-treating agent used as a single composition by mixing a plurality of compositions upon use is included in the one-part type fiber-treating agent, and “the pH of the fiber-treating agent” refers to pH after mixing.

When the pH of the fiber-treating agent is 2.0 or more and less than 6.5, the content of the component (A) in the fiber-treating agent is, in an undissociated form in the case of a salt, preferably 0.1 mass % or more, more preferably 0.2 mass % or more, further more preferably 0.5 mass % or more, even more preferably 1.0 mass % or more, from the viewpoint of imparting higher shape sustainability, water resistance, stretchability (tenacity, that is, high breaking elongation during fiber tensioning), and heat resistance to treated naturally derived fibers, and is preferably 40 mass % or less, more preferably 30 mass % or less, further more preferably 25 mass % or less, even more preferably 20 mass % or less, even more preferably 15 mass % or less, from the viewpoint of improving the feel of the fiber surfaces.

That is, when the pH of the fiber-treating agent is 2.0 or more and less than 6.5, the content of the component (A) in the fiber-treating agent of the present invention is, in an undissociated form in the case of a salt, preferably from 0.1 to 40 mass %, more preferably from 0.2 to 30 mass %, further more preferably from 0.5 to 25 mass %, even more preferably from 1.0 to 20 mass %, even more preferably from 1.0 to 15 mass %, from the above viewpoint.

When the pH of the fiber-treating agent is 6.5 or more and 11.0 or less, the content of the component (A) in the fiber-treating agent is, in an undissociated form in the case of a salt, preferably 1.0 mass % or more, more preferably 2.0 mass % or more, further more preferably 5.0 mass % or more, even more preferably 10 mass % or more, from the viewpoint of imparting higher shape sustainability, water resistance, stretchability (tenacity, that is, high breaking elongation during fiber tensioning), and heat resistance to treated naturally derived fibers, and is preferably 90 mass % or less, more preferably 80 mass % or less, further more preferably 70 mass % or less, even more preferably 60 mass % or less, from the viewpoint of improving the feel of the fiber surfaces.

That is, when the pH of the fiber-treating agent is 6.5 or more and 11.0 or less, the content of the component (A) in the fiber-treating agent of the present invention is, in an undissociated form in the case of a salt, preferably from 1.0 to 90 mass %, more preferably from 2.0 to 80 mass %, further more preferably from 5.0 to 70 mass %, even more preferably from 10 to 60 mass %, from the above viewpoint.

The component (B) is a radical initiator for polymerizing the component (A). The component (B) may be contained in the composition containing the component (A), but when the fiber-treating agent to be used is made into a multiple-part type, for example, a two-part type, the component (B) may be contained in a composition (the second part) different from the composition containing the component (A) (the first part). Examples of the component (B) include a peroxide initiator and an azo initiator. Examples thereof also include a combination of an oxidizing agent and a reducing agent as a redox initiator.

Examples of the peroxide initiator include sodium persulfate, potassium persulfate, ammonium persulfate, t-butyl hydroperoxide, t-amyl hydroperoxide, p-diisopropylbenzene hydroperoxide, cumene hydroperoxide, pinane hydroperoxide, p-menthane hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, benzoyl peroxide, t-butyl perbenzoate, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di(2-ethoxyethyl) peroxydicarbonate, t-butyl peroxyneodecanoate, t-butyl peroxypivalate, (3,5,5-trimethylhexanoyl)peroxide, dipropionyl peroxide, and diacetyl peroxide.

Examples of the azo initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis(2-methylbutyronitrile), 1,1′-azobis(cyclohexane-1-carbonitrile), 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), 2,2′-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.

Examples of the oxidizing agent used in the redox initiator include hydrogen peroxide, sodium hypochlorite, potassium hypochlorite, oxygen, and ozone, in addition to the above-described compounds exemplified as the peroxide initiator. Examples of the reducing agent used in the redox initiator include sodium sulfite, potassium sulfite, sodium hydrogen sulfite, potassium hydrogen sulfite, sodium pyrosulfite, potassium pyrosulfite, iron(II) ion, chromium ion, ascorbic acid, formaldehyde sulfoxylate, tetramethylene diamine, and sodium hydroxymethanesulfinate.

The fiber-treating agent for hydrophilic naturally derived fibers is preferably an aqueous solution from the viewpoint of promoting penetration of the compound in the solution into fibers, and therefore, also as the radical initiator to be formulated in the fiber-treating agent, a water-soluble radical initiator is preferable. As the water-soluble azo initiator, 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, 2,2′-azobis[2-(2-imidazolin-2-yl)propane]dihydrochloride, or the like is preferable.

Here, the water-soluble radical initiator refers to, in the following terms showing the degree of solubility which is defined by the volume (mL) of water required to dissolve 1 g of radical initiator powder within 30 minutes when the powder is put in water and vigorously shaken for 30 seconds every 5 minutes at 20° C.±5° C. in accordance with JIS K8001 general rules for test methods of reagents, a radical initiator preferably corresponding to “slightly soluble” to “very soluble”, more preferably “sparingly soluble” to “very soluble”, further more preferably “soluble” to “very soluble”, even more preferably “freely soluble” to “very soluble”, even more preferably “very soluble”.