JPH06306765A - Collagen fiber good in water resistance - Google Patents

Abstract

PURPOSE:To provide a regenerated fiber completely free from a color and excellent in water resistance by adding a specific amount of an aluminum salt to a regenerated collagen fiber. CONSTITUTION:The split leather of an animal is treated by an alkali solubilizing method or by an enzymatic solubilizing method, and the produced solubilized collagen is dissolved in an acidic solution prepared from an inorganic acid, an organic acid, etc., and subsequently spun into water-swollen regenerated collagen fibers, which are immersed in an aqueous solution of a basic aluminum chloride to produce regenerated collagen fibers containing the aluminum chloride in an amount of 8-20wt.% expressed in terms of aluminum oxide. The produced regenerated collagen fibers never have such a color as produced by a conventional treatment using a chromium salt, and are excellent in water resistance. The aluminum salt is preferably basic aluminum chloride or basic aluminum sulfate.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a regenerated collagen fiber having good water resistance. More specifically, the present invention relates to a regenerated collagen fiber which is suitable for use in hair and fur fibers, surgical threads, non-woven fabrics, papers, etc. and has excellent coloring and water resistance.

[0002]

2. Description of the Related Art In general, in order to produce regenerated collagen fibers, animal skin or bone is used as a raw material, and this is subjected to alkali or enzyme treatment to decompose and remove the telopeptide portion of collagen and to dissolve collagen in water. And the method of spinning this is adopted. Therefore, the obtained regenerated collagen fiber is also soluble in water, and when the regenerated collagen fiber contains water, the water resistance is deteriorated such that the regenerated collagen fiber starts to shrink at a temperature of about 30 to 40 ° C. Therefore, it cannot be used for the above applications.

Therefore, as a method for improving the water resistance of the obtained regenerated collagen fiber, a method of applying a metal salt tan such as a chromium salt, an aluminum salt, a zirconium salt, a titanium salt, an iron salt (Japanese Patent Publication No. 43-12633). Japanese Patent Publication No. 45-15295) and a method of applying aldehyde tanning such as formaldehyde and glutaraldehyde.

Among the methods for applying tanning, chromium salt tanning is an effective method for water resistance, but the regenerated collagen fiber obtained by applying chrome salt tanning is colored green, so its application Was restricted. Further, as a method other than the chromium salt tan, for example, there is a method in which aluminum salt tan, zirconium salt tan, formaldehyde tan, etc. are not colored, but all of them have insufficient water resistance.

[0005]

In view of the above-mentioned prior art, the present inventors have aimed to obtain regenerated collagen fibers which are not colored and have excellent water resistance such as improved hot water shrinkage. As a result of intensive studies, a regenerated collagen fiber having all of these physical properties was finally found, and the present invention was completed.

[0006]

According to the present invention, an aluminum salt is allowed to act and converted into aluminum oxide at 8 to 20.
The present invention relates to a regenerated collagen fiber containing a weight% of aluminum salt. The present invention is a regenerated collagen fiber characterized by containing a large amount of aluminum salt in the fiber when tanning with an aluminum salt, and contains 8 to 20% by weight of aluminum salt in terms of aluminum oxide. By doing so, a regenerated collagen fiber that is not colored and has excellent water resistance is obtained.

If the content of aluminum salt in the regenerated collagen fiber is less than 8% by weight in terms of aluminum oxide, the water resistance is practically insufficient, and if it exceeds 20% by weight, the water resistance is good. However, the fibers become hard and the texture of the collagen fibers is impaired.

In order to contain a large amount of aluminum salt in the regenerated collagen fiber, it is preferable to treat the regenerated collagen fiber in a state of being sufficiently swollen with water in advance. When the regenerated collagen fiber sufficiently swollen with water is then immersed in an aqueous solution of an aluminum salt, the aluminum salt penetrates sufficiently and the content of the aluminum salt in the fiber increases.

The aluminum salt used here is not particularly limited, but a basic aluminum salt having high reactivity with collagen is preferable. Further, basic aluminum chloride or basic aluminum sulfate represented by the following formula is more preferable.

Al (OH) _n Cl _3-n or Al ₂ (OH) _2n (SO ₄ ) _3-n [wherein n is 0.5 to 2.5] In the present invention, regenerated collagen is used. As a raw material of fiber,
For example, fresh hides after slaughter of animals such as cows or floor hides obtained from salted hides are used. Most of these floor skins and the like are composed of insoluble collagen fibers, but they are usually used after removing the fleshy part adhering to the reticular layer, and removing the salt used for preventing spoilage and deterioration. .

Impurities such as glycerides, phospholipids, free fatty acids, and other lipids, glycoproteins, proteins such as albumin, and other proteins other than collagen are present in the insoluble collagen fibers. The spinning stability, quality such as gloss and strength and elongation, and odor have a great influence.For example, lime is used to hydrolyze the fat content in the insoluble collagen fiber, and the collagen fiber is unraveled and then acidified. It is desirable to remove these impurities in advance by subjecting the leather treatment that has been generally performed conventionally, such as alkali treatment, enzyme treatment, and solvent treatment.

The insoluble collagen treated as described above is then subjected to a solubilization treatment in order to cleave the cross-linked peptide portion of the insoluble collagen. As a method of such solubilization treatment, a known and generally adopted alkali solubilization method, enzyme solubilization method, or the like can be applied.

When the alkali solubilization method is applied, it is preferably neutralized with an acid such as hydrochloric acid. As an improved method of the conventionally known alkali solubilization method, the method described in Japanese Patent Publication No. 46-15088 may be adopted. The enzyme solubilization method has an advantage that regenerated collagen having a uniform molecular weight can be obtained, and is a method that can be suitably adopted in the present invention. As such an enzyme solubilization method, for example, Japanese Patent Publication Sho
The method described in, for example, 48-27518 can be adopted. In the present invention, the alkali solubilization method and the enzyme solubilization method may be used in combination.

When the solubilized collagen is further subjected to treatments such as pH adjustment, salting-out, washing with water and solvent treatment, regenerated collagen fibers having excellent quality can be obtained. Therefore, it is preferable to perform these treatments.

The resulting solubilized collagen is then adjusted to pH 2 with hydrochloric acid, acetic acid, lactic acid or the like so as to have a predetermined concentration of, for example, 1 to 15% by weight, particularly 2 to 10% by weight.
It dissolves in an acidic aqueous solution adjusted to 4.5. The obtained collagen aqueous solution may be subjected to defoaming under reduced pressure stirring if necessary, or may be filtered in order to remove fine dust which is a water-insoluble matter.

If necessary, the collagen aqueous solution obtained as described above may be further improved in mechanical strength, for example.
Additives such as stabilizers and water-soluble polymer compounds may be added in appropriate amounts for the purposes of improving water resistance, heat resistance, improving gloss, improving spinnability, preventing coloring, and preserving.

Next, the collagen aqueous solution is discharged through, for example, a spinning nozzle and immersed in the 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, and the concentration of the inorganic salt is usually adjusted to 10 to 40% by weight. However, the type and concentration of these aqueous solutions are not limited to those described above.

The pH of the inorganic salt aqueous solution is, for example, a metal salt such as sodium borate or sodium acetate, hydrochloric acid, acetic acid,
By adding sodium hydroxide or the like, usually 2
It is desirable to adjust it to be 13, preferably 4-12. If the pH is less than 2 or more than 13, the peptide bond of collagen is likely to be hydrolyzed, and it tends to be difficult to obtain the target fiber. Further, the temperature of the inorganic salt aqueous solution is not particularly limited,
Usually, it is preferably 35 ° C or lower. This temperature is 35
If it is higher than ℃, soluble collagen will be denatured,
The strength of the spun fiber is reduced and it becomes difficult to manufacture a stable yarn. The lower limit of this temperature is not particularly limited and may be appropriately adjusted usually according to the solubility of the inorganic salt.

Further, an aldehyde compound such as formaldehyde, glutaraldehyde, glyoxal or dialdehyde starch may be added to the aqueous solution of the inorganic salt in order to improve the fiber openability. When an aldehyde compound is added to an aqueous solution of an inorganic salt, a crosslinking reaction with collagen occurs, the fiber is not dissolved in water, and there is an advantage that washing with water can be performed to remove the inorganic salt contained during spinning.

The regenerated collagen fiber thus obtained is swollen with water or an aqueous solution of an inorganic salt. This swelling is 4 to the weight of the regenerated collagen fiber.
A state containing 15 times as much water or an aqueous solution of an inorganic salt is preferable.
If the content of water or an aqueous solution of an inorganic salt is less than 4 times, the content of aluminum salt in the regenerated collagen fiber is small and the water resistance is insufficient, and if it exceeds 15 times, the strength of the fiber becomes weak and the handling becomes difficult. Is difficult.

The swollen regenerated collagen fibers are then immersed in an aqueous solution of aluminum salt. The aluminum salt of this aluminum salt aqueous solution has the following formula: Al (OH) _n Cl _3-n or Al ₂ (OH) _2n (SO ₄ ) _3-n [where n is 0.5 to 2.5 And basic aluminum chloride or basic aluminum sulfate is preferable. Specifically, for example, aluminum sulfate, aluminum chloride, alum, etc. are used. These aluminums can be used alone or in combination of two or more. The aluminum salt concentration of this aluminum salt aqueous solution is 0.3 to 5% by weight in terms of aluminum oxide.
Is preferred. The concentration of this aluminum salt is
If it is less than 0.3% by weight, the content of aluminum salt in the regenerated collagen fiber is small and the water resistance is insufficient.
If the amount is more than wt%, the treated fiber becomes hard and the texture is impaired.

The pH of the aluminum salt aqueous solution is usually adjusted to 2.5 to 5 using hydrochloric acid, sulfuric acid, acetic acid, sodium hydroxide, sodium carbonate or the like. This pH is
If it is less than 2.5, the structure of collagen tends to be broken and denatured, and if it exceeds 5, aluminum salt will be precipitated and it will be difficult to penetrate into the fiber. This p
First, H is adjusted to 2.2 to 3.5 so that the aqueous solution of aluminum salt is sufficiently permeated into the regenerated collagen fiber, and then 3.5 to 5 is added by adding sodium hydroxide, sodium carbonate or the like. It is preferable to adjust the pH to 5 to complete the treatment, but when using a highly basic aluminum salt, the initial pH adjustment of 2.5 to 5 may be sufficient.

The liquid temperature of the aluminum salt aqueous solution is not particularly limited, but is preferably 50 ° C. or lower. If this liquid temperature exceeds 50 ° C, the regenerated collagen fibers tend to be denatured.

The time for immersing the regenerated collagen fiber in this aluminum salt aqueous solution is 3 hours or more, preferably 6 to
25 hours. If the immersion time is less than 3 hours, the reaction of the aluminum salt is difficult to proceed, and the water resistance of the regenerated collagen fiber becomes insufficient. Although the upper limit of the immersion time is not particularly limited, the reaction of the aluminum salt sufficiently progresses within 25 hours and the water resistance becomes good.

In order to prevent the aluminum salt from being rapidly absorbed in the regenerated collagen fiber and causing unevenness in concentration, an inorganic salt such as sodium chloride, sodium sulfate, potassium chloride is appropriately added to the aqueous solution of the aluminum salt. May be.

The regenerated collagen fiber thus treated with the aluminum salt is then washed with water, oiled and dried. The regenerated collagen fiber thus obtained is completely free from the coloring as treated with the conventional chromium salt, and
It is clear that the advantages of the present invention are great because of its excellent water resistance.

[0027]

EXAMPLES Next, the method for treating regenerated collagen fiber of the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. In the present invention, the following methods were used to measure the content of aluminum salt in the regenerated collagen fiber, the hot water shrinkage of the regenerated collagen fiber, the water absorption rate, and the swelling state.

(1) Aluminum salt content 105 regenerated collagen fibers treated with aluminum salt
Drying in a soaking oven at ℃, the weight when it becomes a constant weight is W ₀ , the ash content after treating this fiber in the oven at 600 ℃ is W _al, and the fiber before treatment with aluminum salt is The amount of ash after being dried at 80 ° C. and treated in an oven at 600 ° C. was defined as W, and was calculated from the following formula [1].

“Aluminum oxide content” = {(W _al −W) / W ₀ } × 100 [1] (2) Hot water shrinkability A fiber bundle having a test length of 30 cm and a total fineness of 2000 d was added to hot water at 70 ° C. After soaking for 30 minutes, it was dried and the test length was measured, and the shrinkage rate was calculated based on the following formula [2].

“Shrinkage rate” = {(30−L) / 30} × 100 [2] (In the formula, L represents a test length after immersion) (3) Water absorption rate Fiber is heated in hot water at 50 ° C. for 1 hour Immerse it to absorb water sufficiently,
The weight after wiping off the water adhering to the surface of the fiber was W, and the weight when it was dried in a soaking oven at 105 ° C. to a constant weight was W _{0, and} was determined from the following formula [3].

“Water absorption rate” = {(W−W ₀ ) / W ₀ } × 100 [3] (4) Swelling state Fibers containing water after spinning or an aqueous solution of an inorganic salt are attached to the fiber surface by a filter paper or the like. Let W _b be the weight after wiping off the water, and then let W _{0 be} the weight when it was dried in a soaking oven at 80 ° C. and cooled in a desiccator to a constant weight.
Was calculated as the swelling degree.

“Swelling degree” = (W _b −W ₀ ) / W ₀ [4] When an aqueous solution of an inorganic salt is contained, it is immersed in a 1% aqueous formaldehyde solution for 5 minutes so that it does not dissolve in water. After rinsing with water, the degree of swelling was measured.

Example 1 Using bovine bark as a raw material, solubilized with alkali, dissolved in an aqueous lactic acid solution, and adjusted to pH 3.2 and collagen concentration of 6.2% by weight, a stock solution was stirred and defoamed under reduced pressure. Then, the solution was transferred to a piston-type spinning stock solution tank, and then allowed to stand still under reduced pressure for defoaming. This stock solution was extruded with a piston, then quantitatively fed with a gear pump, filtered through a sintered filter with a pore size of 10 μm, passed through a spinning nozzle consisting of a pore size of 0.3 mm, a pore length of 0.5 mm, and a number of pores of 50, and boric acid and water PH 1 with sodium oxide
It was discharged to a coagulation bath at 25 ° C. containing 20% by weight of sodium sulfate adjusted to 0. Then 15% by weight of sodium sulfate adjusted to pH 9 with boric acid and sodium hydroxide
And 0.5% by weight of formaldehyde were introduced into a coagulation bath at 25 ° C., and the mixture was immersed for 1 minute so as to be insoluble in water to react with formaldehyde, and then washed at 25 ° C. with water. The swelling degree of the regenerated collagen fiber after washing with water was measured to be 7.8.
It was double. Next, the fibers swollen with water were placed in an aqueous solution containing 10% by weight of basic aluminum chloride (basicity 50%, aluminum content 28% by weight converted to aluminum oxide) and 15% by weight of sodium chloride at 25 ° C.
Soak for hours. Then, the obtained fiber is washed with warm water at 40 ° C., then an emulsion of amino-modified silicone with an amine equivalent of 3000 and an oil agent consisting of a pluronic type polyether antistatic agent are attached and tensioned in a hot air dryer at 60 ° C. Dried under.

The obtained regenerated collagen fiber contained 13.5% by weight of aluminum salt in terms of aluminum oxide, had no harmful coloring, had a fineness of 62 d and a tensile strength of 2.9 g / d. The elongation was 28%, the Young's modulus was 480 kg / mm ² , the hot water shrinkage at 70 ° C. was 7%, and the water absorption was 84%, indicating good water resistance.

Example 2 In Example 1, basic aluminum chloride (basicity 50
%, Aluminum content converted to aluminum oxide 2
8 wt%) was changed to 5 wt%.

The regenerated collagen fiber thus obtained contained 12.2% by weight of aluminum salt in terms of aluminum oxide, had no harmful coloring, had a fineness of 61 d and a tensile strength of 2.7 g / d. The elongation was 28%, the Young's modulus was 470 kg / mm ² , the hot water shrinkage at 70 ° C. was 8%, and the water absorption was 92%, indicating good water resistance.

Example 3 The procedure of Example 1 was repeated except that the basic aluminum chloride was changed to 3% by weight. The obtained regenerated collagen fiber contains 10.4% by weight of aluminum salt in terms of aluminum oxide, has no harmful coloring, has a fineness of 60 d, a tensile strength of 2.9 g / d and an elongation of 28. %, Young's modulus 470 kg / mm
² , the hot water shrinkage at 70 ° C. was 9% and the water absorption was 95%, indicating good water resistance.

Example 4 In Example 1, basic aluminum chloride (basicity 52
%, Aluminum content converted to aluminum oxide 1
8 wt%) and 15 wt%.

The regenerated collagen fiber thus obtained contained 8.3% by weight of aluminum salt in terms of aluminum oxide, had no harmful coloring, had a fineness of 57 d and a tensile strength of 2.9 g / d. The elongation was 30%, the Young's modulus was 470 kg / mm ² , the hot water shrinkage at 70 ° C. was 10%, and the water absorption was 110%, indicating good water resistance.

Comparative Example 1 The procedure of Example 1 was repeated except that the basic aluminum chloride was changed to 1% by weight. The obtained regenerated collagen fiber contained 6.8% by weight of aluminum salt in terms of aluminum oxide, had no harmful coloring, had a fineness of 56 d, a tensile strength of 2.8 g / d and an elongation of 26. %, Young's modulus 490 kg / mm ²
However, the hot water shrinkage at 70 ° C was 23% and the water absorption was 15
It was 8% and the water resistance was poor.

Comparative Example 2 The washed yarn after spinning in Example 1 was dried under tension in a hot air dryer at 60 ° C. to remove water in the fiber, and then immersed again in water. The swelling degree at this time was 3.2. Then it was treated with basic aluminum chloride according to Example 1.

The regenerated collagen fiber thus obtained contained 7.2% by weight of aluminum salt in terms of aluminum oxide, had no harmful coloring, had a fineness of 52 d and a tensile strength of 2.8 g / d. The elongation was 26% and the Young's modulus was 480 kg / mm ² , but the hot water shrinkage at 70 ° C was 32% and the water absorption was 172%.
And the water resistance was poor.

[0043]

EFFECTS OF THE INVENTION The regenerated collagen fiber obtained by the present invention has no coloring unlike the treatment with the conventional chromium salt and is excellent in water resistance, so that the advantages of the present invention are great. That is clear.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Atsushi Sasayama 2-63 Okihama-cho, Takasago-cho, Takasago-shi, Hyogo (72) Inventor Yo Tanaka 1 Hokuyo Co., Ltd., 57, Sansha, Yamagata-shi (72) Inventor Munenori Yuguchi 1 Hokuyo Co., Ltd., 57, Sansha, Yamagata City, Yamagata Prefecture (72) Kazuhiko Takahisa 1 Hokuyo Co., Ltd., 57, Sansha, Yamagata City (72) Inventor, Hitomi Edamatsu Yamagata Prefecture 1 Hokuyo Co., Ltd. at 57, Sansha, Yamagata (72) Inventor Shingo Nakazaki 1 Hokuyo Co., Ltd. at 57, Sansha, Yamagata, Yamagata Prefecture

Claims (3)

[Claims] 1. A regenerated collagen fiber containing an aluminum salt in an amount of 8 to 20% by weight in terms of aluminum oxide by acting an aluminum salt. 2. The regenerated collagen fiber according to claim 1, wherein the aluminum salt is basic aluminum chloride or basic aluminum sulfate represented by the following formula. _{Al (OH) n Cl 3-} n, or _{Al 2 (OH) 2n (SO} 4) 3-n [ wherein, n is 0.5 to 2.5] 3. A method for producing regenerated collagen fiber, which comprises immersing regenerated collagen fiber swollen 4 to 15 times with water in an aqueous solution of an aluminum salt and treating it.