JP3578227B2 - Easy fibrillated polynosic fiber and method for producing the same - Google Patents

Description

【００１６】
実施例３〜４，比較例３
実施例１と同一条件で製造されたビスコースを実施例１の第４浴の硫酸濃度を２５０ｇ／リットルに保持して浴温度を変更した。得られた糸の特性を表２に示す。
【００１７】
【表２】

【００１８】
【発明の効果】
本発明により製造される繊維はフィブリル化潜在能力の高い特性を備えている。本発明によって得られたポリノジック繊維を用いると合理化された手段でもって抄紙分野、衣料分野等に適合する。
【図面の簡単な説明】
【図１】本発明繊維の走査型電子顕微鏡写真（５００倍）から写し取った図である。
【図２】本発明繊維を王研式ビーターで３０分間叩解した後の繊維の走査型電子顕微鏡写真（５００倍）から写し取った図である。
【符号の説明】
１：ファイバー， ２：フィブリル， ３：ミクロフィブリル[0001]
[Industrial applications]
The present invention provides a polynosic fiber which is easily fibrillated and a method for producing the same.
[0002]
[Prior art]
In the cellulose fiber, molecules aggregate, microfibrils, and microfibrils aggregate to form fibrils.
[0003]
However, since cellulose has a large number of strong hydrogen bonds between molecules, it has been said that it is difficult to make fibrils into smaller units by an ordinary method. Conventionally, as a method for making cellulose fibers finer or fibrillated, mechanical treatment such as refiner and ball mill, physical treatment such as explosion, and chemical treatment such as microcrystallization treatment have been performed. In particular, when the viscose fiber is limited, in the case of JP-A-6-128874, a woven or knitted fabric composed of polynosic fiber having a high degree of polymerization having an average degree of polymerization of 600 or more is subjected to a normal pressure washer, a continuous relaxation machine, and a liquid. There is a production method in which a wet dyeing process is performed in a flow dyeing machine or a wince dyeing machine, or fibrillation is performed by a method of rubbing by a stone wash method. In the case of JP-A-6-108306, a high-strength, low-elongation polynosic fiber having a tensile strength of 4 to 6 g / d and a tensile elongation of 8% or less in a standard state is fibrillated by an external force in a wet state. There is a way.
[0004]
However, the method described in JP-A-6-128874 is composed of polynosic fibers having a high degree of polymerization of an average degree of polymerization of 600 or more. Japanese Patent Application Laid-Open No. 6-108306 discloses a high-strength, low-elongation polynosic fiber having a tensile strength of 4 to 6 g / d and a tensile elongation of 8% or less under standard conditions. The fibrillation potential of the fiber obtained by these high polymerization degree, high strength (necessarily low elongation) polynosic fiber is low, and it can be obtained by subsequent wet rubbing, friction, or beating. In order to beat to a predetermined state, for example, a process of greatly increasing the processing time is required. Long-term treatment in a wet state has disadvantages such as remarkably impairing the quality of the obtained product.
[0005]
[Problems to be solved by the invention]
The present invention has been made to solve the above problems. That is, the present invention provides a polynosic fiber having extremely high fibrillation potential and a method for producing the same.
[0006]
[Means for Solving the Problems]
Means for solving the above-mentioned problems, that is, the present invention provides a process for producing a polynosic fiber by a low-acid low-temperature spinning method of viscose having a high degree of polymerization to obtain a yarn that has not been completely regenerated and has a residual γ value of 1 to 20. And immediately complete the regeneration through an acid bath having a sulfuric acid concentration of 30 to 300 g / liter and a temperature of 70 ° C. or higher, and a freeness of 600 cc measured by a Canadian standard type with a beating time of 30 minutes. A polynosic fiber obtained by the method according to claim 1 which is as follows.
[0007]
The first step in the present invention is a viscose coagulation step in the first bath, but may be a low acid concentration, low temperature bath generally used. Since the optimum conditions for the first bath are related to the viscose conditions and the spinning conditions such as spinning speed, bath temperature, bath length, etc., it is not possible to control only these conditions alone, but as a general range, the sulfuric acid concentration is 15 to 30 g. The concentration is 0.1 to 3 g / liter zinc sulfate / 100 g / liter sodium sulfate concentration and 28 ° C. or lower. The second step is a regenerating step of the yarn in the second bath which is generally performed, but may be a low acid concentration and low temperature bath which is generally performed. Since the optimum conditions of the second bath are related to the spinning conditions as in the first bath described above, it is not possible to regulate only this, but the sulfuric acid concentration is 5 to 15 g / l, the zinc sulfate concentration is 3 g / l or less, and the sodium sulfate concentration is The temperature is not more than 50 g / liter and the temperature is not more than 28 ° C. The third step is a yarn drawing step, in which the yarn is drawn to a draw ratio at which desired yarn physical properties are obtained. The fourth step is a step of decomposing and regenerating the yarn fixed in the third step, but may be performed at a generally high temperature and a low acid concentration. Since the optimum conditions of the third bath are related to the spinning conditions as in the case of the above-mentioned first bath, it is not possible to regulate only this, but the sulfuric acid concentration is 5 g / l or less and the temperature is 95 ° C. or more. The residual γ value of the yarn that has passed through the fourth step usually falls between 1 and 20. The fifth step is particularly important in the present invention, and the intended effects of the present invention can be obtained only when the conditions specified in the present invention are satisfied.
[0008]
The fifth step of the present invention is a step of treating the yarn having a residual γ value of 1 to 20 that has passed through the fourth step with a sulfuric acid concentration of 30 to 300 g / liter at a temperature of 70 ° C. or more and a bath residence time of 1 to 300 seconds. A more preferred concentration of sulfuric acid is in the range of 50-250 g / l. Here, at a sulfuric acid concentration of 30 g / liter or less, a desired polynosic fiber which is easily fibrillated cannot be obtained. Conversely, if the concentration of sulfuric acid is 300 g / liter or more, the strength and elongation of the fiber decrease, which is not practical. The bath temperature is preferably 70 ° C. or higher. If the temperature is lower than 70 ° C., carbon disulfide contained in the yarn hardly volatilizes, and the strength and elongation of the fiber decrease, which is not practical. Since the bath residence time is related to the sulfuric acid concentration condition, it cannot be regulated alone, but the optimal range is 1 to 300 seconds as a general range. The residual γ value of the yarn that has passed through the fifth step is 0 to 1. Thereafter, if necessary, it may be introduced into a final heat bath to completely decompose and regenerate.
[0009]
The present invention is achieved by treating an undecomposed and swollen yarn having a residual γ value of 1 to 20 at a high acid concentration and a high temperature. This is presumably because, within the scope of the present invention, the hydrogen bond of the cellulose molecule is partially broken, and the bonding force of fibrils or microfibrils in the direction perpendicular to the fiber axis is weakened. As a result, it is considered that the fiber has a high fibrillation potential and is easily microfibrillated by a subsequent mechanical or physical external force in a wet state.
[0010]
【Example】
Hereinafter, the present invention will be described in detail with reference to examples.
[0011]
In the examples, methods for measuring the γ value used in the evaluation and the freeness of the Canadian standard form are described below.
[0012]
An unregenerated cut yarn equivalent to 0.25 to 0.35 g of γ-cellulose is collected in a saturated solution of ammonia and an alkaline ammonium salt cooled to 0 to 4 ° C., the decomposition is stopped, and the mixture is left for 5 minutes. Replace any remaining xanthate groups with ammonium cations. Then, the mixture is thoroughly washed several times with a mixture of water and alcohol 4: 6 cooled to 0 to 4 ° C. while exchanging the solution several times to remove free ammonium ions. After completion of the purification, it is decomposed with 0.5% hydrochloric acid preliminarily heated to 50 ° C. to produce NH 4 C. This decomposed liquid is filtered and washed, and the yarn is dried to obtain a fibrous content (Sg). The filtrate is put into a flask, made alkaline with 20% NaOH, connected to a condenser and distilled to distill and distill the ammonia into 0.1N H2SO4 (Acc). After confirming that the ammonia is completely distilled, , Back titration with NaOH.
(Bcc) From the above measurement, the amount of xanthate groups remaining in the yarn is shown as follows.
Residual γ value (%) = (AB) /S×1.62
[0013]
Freeness of canadenian standard form Measured according to JIS P8121.
300 g of the fiber (in terms of absolute dry weight) was disintegrated in 10 liters of water, and beaten with an Oken beater for 30 minutes. The beaten fiber was subjected to tapping paper making at a target weight of 80 g / cm ² , and after dehydration, the wet paper was dried at 120 ° C. and measured. The smaller the value of the freeness, the greater the fibrillation and the greater the entanglement of the fibers.
[0014]
Examples 1-2, Comparative Examples 1-2
Viscose having a cellulose content of 4.7%, an alkali concentration of 2.5%, a γ value of 75, a falling ball viscosity of 230 seconds and an average degree of polymerization of 550 was adjusted by a conventional method. This was spun from a nozzle having a hole diameter of 0.06 mm and a number of holes of 27,000 in a bath containing 18.0 g / l of sulfuric acid, 0.5 g / l of zinc sulfate and 20 g / l of sodium sulfate at a temperature of 28 ° C to solidify viscose. Was. Next, the yarn was regenerated in two baths containing 27 g / liter of sulfuric acid and 23 g / liter of sodium sulfate at a temperature of 27 ° C., and the yarn was stretched by 55%. Next, it was regenerated and decomposed in three baths at a bath temperature of 97 ° C. and sulfuric acid of 1.0 g / liter. The resulting yarn had a residual γ value of 10. Next, the yarn was treated in a fourth bath having a temperature of 90 ° C. and a bath length of 2 m (bath residence time of 5 seconds) at 250 g / liter of sulfuric acid (Example 1) and 50 g / liter (Example 2). The residual γ value of the obtained yarn was 1. After the yarn was taken out into the air, it was completely decomposed in a heat bath in the final step. Next, a scouring treatment and a drying treatment were performed by a conventional method. As a comparative example, a case where only the sulfuric acid concentration of the fourth bath was changed will be described. Table 1 shows the properties of the obtained yarn. FIG. 1 is a photograph taken from a scanning electron micrograph (× 500) of the fiber obtained in Example 1, and the fiber obtained after beating the fiber obtained in Example 1 with an Oken beater for 30 minutes. 2 is a photograph taken from a scanning electron micrograph (× 500) of FIG.
[0015]
[Table 1]

[0016]
Examples 3 to 4, Comparative Example 3
The temperature of the viscose produced under the same conditions as in Example 1 was changed while maintaining the sulfuric acid concentration in the fourth bath of Example 1 at 250 g / liter. Table 2 shows the properties of the obtained yarn.
[0017]
[Table 2]

[0018]
【The invention's effect】
The fibers produced according to the present invention have properties of high fibrillation potential. When the polynosic fiber obtained by the present invention is used, it is adapted to the papermaking field, the garment field, and the like by rationalized means.
[Brief description of the drawings]
FIG. 1 is a photograph taken from a scanning electron micrograph (× 500) of a fiber of the present invention.
FIG. 2 is a photograph taken from a scanning electron micrograph (× 500) of the fiber of the present invention after beating it with an Oken beater for 30 minutes.
[Explanation of symbols]
1: fiber, 2: fibril, 3: microfibril

Claims (2)

In the production process of polynosic fiber by low acid low temperature spinning method of high polymerization degree viscose, a yarn which is not completely regenerated and has a residual γ value of 1 to 20 is obtained, and a sulfuric acid concentration of 30 to 300 g / liter and a temperature of 70 ° C are immediately obtained. A method for producing a polynosic fiber, wherein regeneration is completed through the above acid bath. The polynosic fiber obtained by the method according to claim 1, wherein the freeness measured in Canadian standard form for 30 minutes is 600 cc or less.

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