WO2006043661A1 - Hollow acrylic synthetic fiber - Google Patents

Abstract

This invention provides an acrylic synthetic fiber which is large in fineness, lightweight, soft, and good in hair handling, and has matte effect. The acrylic synthetic fiber is a hollow acrylic synthetic fiber that has a major axis/minor axis of not less than 3 in fiber section, has a hollow part and has a single fiber light transmittance (580 to 600 nm) of not more than 70%. Further, the hollow acrylic synthetic fiber is also preferably one prepared by spinning-twisting a spinning stock liquid comprising an acrylonitrile copolymer through a spinneret having three or more ranged holes of at least one shape selected from circle, ellipse, and rhombus into a coagulating bath, drying the fiber at a low temperature and further heat treating the fiber at 120 to 180˚C.

Description

 Hollow acrylic synthetic fiber

 Technical field

 TECHNICAL FIELD [0001] The present invention relates to a hollow acrylic synthetic fiber that is suitable mainly for pile applications and is lightweight, soft and has a bristle and matting effect.

 Background art

 [0002] Acrylic synthetic fibers are widely used in fields such as bores, seals, fleeces, fibers, and ypiles because of their soft feel and ease of handling. Among the use of the needles, especially those used for clothing are desired to be lightweight, and various proposals have been made for light weight fibers. For example, a hollow acrylic fiber having a core-sheathed two spinning stock solution and having a hollow portion between the core and sheath (Patent Document 1), an acrylic synthetic fiber having a substantially C-shaped cross section spun using a C-shaped nozzle Patent Document 2 proposes an acrylic synthetic fiber (Patent Documents 3 and 4) that forms a hollow portion by forming a skin layer and a core layer and then performing heat treatment. However, these require a complicated process of using two spinning stock solutions and using a core-sheath nozzle (Patent Document 1), and only a cross section close to a circle is possible (Patent Documents 2, 3, and 4). In particular, there was a problem that the tactile sensation was hard and the hair separation was not good at a thick fineness.

 Patent Document 1: JP-A-9-78355

 Patent Document 2: JP 2003-96618

 Patent Document 3: JP-A 61-28014

 Patent Document 4: Republished Patent WOOOZ70133

 Disclosure of the invention

 Problems to be solved by the invention

[0003] An object of the present invention is to obtain an acrylic synthetic fiber that is light and soft, has good brushing properties and has a matting effect at a large fineness.

 Means for solving the problem

That is, the present invention is a cross section in which the major axis Z minor axis of the fiber cross section is 3 or more and has a hollow portion. It is a hollow acrylic synthetic fiber characterized in that 580ηπ! A fiber having a light transmittance of 70% or less at ~ 600 nm is preferred.

[0005] In addition, a spinning solution of acrylonitrile-based polymer is obtained by spinning using a spinneret having holes in which at least one shape selected from a circle, an ellipse, and a rhombus is connected. Is also preferable.

 The invention's effect

 [0006] The hollow acrylic synthetic fiber of the present invention is light and soft and excellent in handling the hair, and also has pores inside the fiber, so that it has a matte and so-called dull feeling expression effect. Therefore, it is particularly suitable for pile fibers having a large fineness, and a lightweight, soft and high-grade pile fabric can be obtained.

 Brief Description of Drawings

[0007] Fig. 1 is an example of a hole shape of a spinneret used in the present invention.

 FIG. 2 is a model diagram of a skin core structure of a fiber cross section taken out of a coagulation bath in the present invention.

 FIG. 3 is a cross-sectional photograph of a fiber after undergoing a hollowing process in the present invention.

 Explanation of symbols

[0008] 1: Skin layer

 2: Core layer

 BEST MODE FOR CARRYING OUT THE INVENTION

[0009] The acrylonitrile-based copolymer in the present invention comprises 30 to 92% by weight of acrylonitrile and 8 to 70% by weight of one or more butyl group-containing monomers copolymerizable with acrylo-tolyl. A copolymerized product is used.

 Bull group-containing monomers that can be copolymerized with acrylonitrile include acrylic acid, methacrylic acid, vinyl chloride, salt vinylidene, pyrbromide bromide, vinylidene bromide, vinyl acetates such as vinyl acetate, or bull pyrrolidone. , Burpyridine and its alkyl-substituted products

, Acrylic acid ester, methacrylic acid ester, acrylic acid amide, methacrylic acid amide or their mono- and dialkyl-substituted products, allylsulfonic acid, methallylsulfonic acid, p-styrenesulfonic acid, 2-acrylamide-2-methylpropanesulfonic acid , Isoprenesulfo Examples include acids and alkali metal salts thereof.

 [0010] This acrylonitrile copolymer is dissolved in an organic solvent such as acetone, acetonitrile, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, or an inorganic solvent such as salty zinc, nitric acid or rhodan salt. Spinning stock solution, but use inorganic or organic pigments or stabilizers effective in anti-mold, anti-coloring, light resistance, etc., or additives that adjust inorganic or organic gloss and whiteness. May be.

 [0011] Next, as shown in FIG. 1, spinning is performed in a coagulation bath through a spinneret having a hole in which three or more shapes selected from a circle, ellipse, or rhombus force are connected. By using these nozzles, the skin core structure formed in the coagulation bath becomes a structure having a relatively large core part inside each circle, ellipse or rhombus, as shown in FIG. Here, in order to form the skin layer, the concentration of the organic solvent or inorganic solvent in the bath or both is preferably 1 to 50% by weight, more preferably 5 to 35% by weight, and the temperature is preferable. Is −10 ° C. to + 50 ° C., more preferably 0 ° C. to + 30 ° C. Then, it passes through a low temperature bath of 10 to 55 ° C, and further passes through a hot water bath of 55 to 95 ° C, preferably 60 to 80 ° C. In these baths, 1.1 to 10 times, preferably Stretches 2-8 times. Then, in order to further reduce the solvent content in the wet yarn, 90 ~: may be passed through saturated steam at LOO ° C!

[0012] When the solvent content is reduced, the hollowing rate tends to increase in the subsequent hollowing step. The wet yarn from the washing bath or from the saturated steam process usually has a liquid content of about 60 to 200% by weight, but is dried at a low temperature of 5 to 70 ° C, preferably 20 to 50 ° C. The liquid content is 5 to 40% by weight, preferably 15 to 30% by weight. At this time, it is considered that a large amount of water and solvent are present in the core. The yarn having the adjusted liquid content is passed through a hollowing process, and by this process, water and solvent present in the core part are instantaneously expanded and volatilized to create a void in the core part. Therefore, the hollowing process may be a general dry heat treatment or hot heat treatment using hot air, etc., as long as the yarn can be rapidly heated, or a constant temperature bath using an organic compound such as polyethylene glycol or glycerin. . It is preferably performed at 120 to 180 ° C for dry heat and wet heat treatment, and at 100 to 140 ° C for a constant temperature bath. As a result, a fiber having voids in the core as shown in FIG. 3 is obtained. After the hollowing step, if necessary, stretching and heat treatment are performed to obtain a fiber having a hollow portion having a generally flat cross-sectional shape. Example

 [0013] The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. Prior to describing the examples, measurement methods and the like will be described.

 [0014] (Measurement method of fiber hollowing ratio)

 The cross-sectional shape of the sample fiber bundle was photographed with a scanning electron microscope at a magnification at which about 100 fiber cross-sections were inserted, and 100 fiber cross-sections with a porosity of 5% or more were hollowed out. And calculated by the following formula.

 Hollowing ratio (%) = [(number of fibers with a porosity of 5% or more) / (number of fibers measured)] X 100 Note that the porosity is a value of a hollow portion that is a hole or a network in the fiber cross section. From the area (A) and the area (B) other than the hollow part, the following formula was used.

 Porosity (%) = [A area Z (A + B area)]

 For the cross section where the hollow part is ruptured and the void part is open toward the fiber surface, the fiber strength and the point force of the texture are not preferred, so the fiber content of such a cross section exceeds 10%. The product was judged not to have adequate performance as a hollow fiber.

 The matte effect was evaluated by measuring the light transmittance of a single fiber.

 [0015] (Measurement method of single fiber light transmittance)

 Using a Olympus Co., Ltd. metal system microscope, the light transmittance of the sample fiber was measured and evaluated at two points for each of five single fibers, for a total of 10 points. The magnification of the objective lens was 50 times and the measurement area was φ = 20 m. A transmission “bright field” neurogen lamp was used as the light source, and measurement was performed in the range of 580 to 600 nm, and the average of the transmittance at these wavelengths was defined as the light transmittance of the sample.

 [0016] (Measurement of liquid content and solvent content)

About 2 g of the fiber to be measured was immersed in 200 g of pure water, and the solvent in the fiber was eluted by boiling at 95 ° C for 30 minutes using a reflux condenser. Thereafter, the immersed fiber was taken out, dried at 110 ° C. for 2 hours, and the weight of the fiber was measured. On the other hand, the solvent concentration in the solution from which the solvent was eluted was measured by gas chromatography (GC-14B) manufactured by Shimadzu Corporation. Fiber weight before soaking Fw, fiber weight after drying Fd, gas chromatography The solvent concentration in the solution measured from 1 was set as c, and the following formula was used.

 Liquid content (%) = [(Fw-Fd) / Fd] X 100

 Solvent content (%) = [C X (200 + Fw-Fd) / Fd] X 100.

 [0017] (Example 1)

 A spinning stock solution (spinning stock solution A) prepared by dissolving an acrylonitrile copolymer consisting of acrylonitrile Z butyl chloride Z sodium styrenesulfonate = 49.5 / 50 / 0.5 in acetone to a polymer concentration of 29%, Acetone Z water = 30Z70, spun into a 20 ° C coagulation bath through a 50-hole nozzle with four holes with a diameter of 0.14 mm in a row and then acetone Z water = 25Z75, 25 ° C bath The film was stretched 1.5 times here. Further, after passing through a water bath at 40 ° C, it was passed through hot water at 75 ° C where it was stretched twice. The liquid content at this stage was 95% by weight, and the acetone content was 9% by weight. Next, low-temperature drying at 40 ° C for 7 minutes reduced the liquid content to 20% by weight and the acetone content to 5%. Thereafter, the fiber was allowed to stay in a 160 ° C. dry heat treatment step for 10 seconds, and water and acetone were expanded and volatilized to develop a hollow portion. Thereafter, the film was further stretched twice at 130 ° C and heat-treated at 145 ° C. The obtained fiber was 22 dtex with a major axis Z minor axis = 4 Zl, a hollowing rate of 92%, and a light transmittance of 60%.

 [0018] (Example 2)

 Spinning stock solution A of Example 1 was spun in the same manner as in Example 1 in which four ellipses with a major axis Z minor axis = 1.5 Z1 (major axis = 0.15 mm) were connected, and contained after low-temperature drying. The liquid ratio was reduced to 20% by weight and the acetone content was reduced to 4%. Thereafter, hollowing treatment and drawing heat treatment were performed, and the obtained fiber was 20 dtex with a major axis Z minor axis = 5 Zl, a hollowing rate of 90%, and a light transmittance of 64%.

 [Example 3]

Spinning stock solution A of Example 1 was spun into a coagulation bath of acetone Z water = 30Z70, 20 ° C through a nozzle with a hole shape of four circles each having a diameter of 0.14 mm, and then acetone Z It passed through a bath of water = 35Z65, 25 ° C., and was stretched twice here. Further, after passing through a water bath at 40 ° C, it was passed through hot water at 75 ° C, where it was stretched twice. At this stage, the liquid content was 87% by weight and the acetone content was 7% by weight. Next, dry at 40 ° C at low temperature 6 By performing minutes, the liquid content 18 weight _^0/0 decreased the containing acetone ratio of 4%. Thereafter, the fiber was allowed to stay in a 160 ° C. dry heat treatment step for 10 seconds, and water and acetone were expanded and volatilized to develop a hollow portion. Thereafter, the film was further stretched 1.5 times at 130 ° C and heat-treated at 145 ° C. The obtained fiber was 22 dtex with a major axis Z minor axis = 4 Zl, a hollowing ratio of 89%, and a light transmittance of 62%.

[0020] (Example 4)

 A spinning stock solution (spinning stock solution B) in which an acrylonitrile copolymer consisting of acrylonitrile Z vinylidene chloride Z sodium styrenesulfonate = 50.0 / 490/1. , It was spun into a coagulation bath of acetone Z water = 30Z70, 20 ° C through a nozzle with a hole shape consisting of four circles with a diameter of 0.14 mm and a number of holes of 50, followed by caseon Z water = 30Z70, 25 ° C. Then, the film was stretched 1.5 times. Further, after passing through a water bath at 40 ° C., it was passed through hot water at 75 ° C., where it was stretched twice.

 Further, it passed through saturated steam at 96 ° C. for 2 minutes, and the liquid content at this stage was 103% by weight and the acetone content was 2% by weight. Next, low temperature drying at 40 ° C. for 6 minutes reduced the liquid content to 21% by weight and the acetone content to 1%. Thereafter, the fiber was allowed to stay in a dry heat treatment step at 165 ° C. for 10 seconds, and water and acetone were expanded and volatilized to develop a hollow portion. Thereafter, the film was further stretched 1.5 times at 135 ° C and heat-treated at 150 ° C. The resulting fiber is 22 dtex with a major axis Z minor axis = 4 Zl, hollowing rate of 95%, and light transmittance of 57%.

[Example 5]

Spinning stock solution B of Example 4 was spun into a coagulation bath of acetone Z water = 30Z70, 20 ° C through a nozzle with a hole shape of 150 holes having a diameter of 0.08 mm and connected in series to a 20 ° C coagulation bath. Z water = 30Z70, passed through a bath at 25 ° C, where 1.5 times stretching was performed. Further, after passing through a water bath at 40 ° C, it was passed through hot water at 75 ° C where it was stretched twice. Furthermore, it passed through saturated steam at 96 ° C for 2 minutes. At this stage, the liquid content was 92% by weight and the acetone content was 2% by weight. Next, low-temperature drying at 40 ° C for 6 minutes reduced the liquid content to 16% by weight and the acetone content to 1%. Thereafter, the fiber was allowed to stay in a 165 ° C. dry heat treatment step for 10 seconds, and water and acetone were expanded and volatilized to develop a hollow portion. After that The film was stretched 1.5 times at 135 ° C and heat-treated at 150 ° C. The obtained fiber was lOdtex having a major axis Z minor axis = 5 Zl, a hollowing ratio of 93%, and a light transmittance of 66%.

 [0022] (Comparative Example 1)

 Spinning stock solution A of Example 1 was spun by the same method as in Example 1 with a major axis Z minor axis = 8 Zl (major axis = 0.66 mm), and the liquid content after low-temperature drying was 15 wt%. The acetone content was reduced to 4%. After that, hollowing treatment was performed at 160 ° C. However, the hollow portion burst, and most of the cross-sections did not remain flat. After that, drawing heat treatment was performed, but the cross-section that did not retain the flat shape was the majority even in the final fiber, the presence ratio of the fiber with the hollow portion ruptured was 55%, and the light transmittance was 60%.

 [0023] (Comparative Example 2)

 Spinning stock solution A of Example 1 was spun by the same method as in Example 1 with a major axis Z minor axis = 8 Zl (major axis = 0.66 mm), and the liquid content after low-temperature drying was 5% by weight. The acetone content was reduced to 2%. Thereafter, the hollowing rate at 160 ° C was 27%, and the light transmittance was 81%.

 [0024] The obtained hollowing ratio, light transmittance, and the existence ratio of the cross-section in which the hollow portion is ruptured are shown.

Shown in 1.

[0025] [Table 1] Hollowing rate Light transmittance Cross section of hollow part ruptured

 %% Existence (%)

 Example 1 9 2 6 0 1

 Example 2 9 0 6 4 0

 Example 3 8 9 6 2 0

 Example 4 9 5 5 7 0

 Example 5 9 3 6 6 1

 Comparative Example 1 3 2 6 0 5 5

 Comparative Example 2 2 7 8 1 0

Claims

The scope of the claims  [1] Long axis of fiber cross section Z short axis is a cross section of 3 or more and has a hollow part, 580ηπ! Hollow acrylic synthetic fiber characterized in that the light transmittance of a single fiber at ˜600 nm is 70% or less.  [2] The hollow according to claim 1, wherein the spinning solution of the acrylonitrile polymer is spun using a spinneret having a hole in which three or more shapes selected from a circle, an ellipse and a rhombus are connected. Acrylic synthetic fiber.