JP2006299473A - Shrinkable acrylic fiber dyeable at low temperature - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an acrylic fiber dyeable at a lower temperature than a temperature for completely developing shrinkage and developing sufficient shrinkage by heating after dyeing. <P>SOLUTION: The shrinkable acrylic fiber dyeable at the low temperature is characterized as follows. The fiber has <15% shrinkage percentage in hot water at ≤75°C and ≥15% shrinkage percentage by a wet heat treatment at 90-100°C or a dry heat treatment at 120-150°C and is dyeable at ≤75°C. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a low temperature dyeable shrinkable acrylic fiber. Specifically, the present invention relates to an acrylic fiber that can be dyed at a temperature lower than the temperature at which shrinkage is fully expressed, and can exhibit sufficient shrinkage after dyeing.

The shrinkable acrylic fiber is a fiber that develops shrinkage when heated. In bulky yarn, sliver knit, and the like, the bulkiness is developed using the shrinkage. On the other hand, in the dyeing of acrylic fibers, the affinity of dyes suddenly increases from around 80 ° C., and hardly dyes below this temperature. Therefore, dyeing is usually performed using a dye bath at 90 ° C. or higher. . However, when the shrinkable acrylic fiber is dyed under such conditions, it shrinks completely, and after the dyeing, the shrinkage can hardly be expressed. Therefore, when bulkiness is required, such as bulky yarn or sliver knit, it is necessary to heat the shrinkable acrylic fiber by dyeing or the like after previously forming the shrinkable acrylic fiber into a yarn, woven fabric, knitted fabric or the like.

Due to this limitation of dyeing, when dyeing in melange, tone, etc., multiple types of fibers that are dyed with different types of dyes in advance at the stage of creating yarn, woven fabric, knitted fabric, etc. You must be able to do it. Further, when blending or knitting with heat-sensitive fibers, the fibers may be damaged by heat during dyeing.

In this regard, in the case of a sliver knit or carpet, use a so-called original fiber colored during the production of shrinkable acrylic fiber, or use a sliver that has been dyed with a tow processing machine after normal tow dyeing. It is possible to However, in the case of original fibers, there is a problem that an arbitrary color cannot be easily obtained, or it is necessary to stock original fibers of many colors and is not suitable for small lot production. . In addition, in the case of tow dyeing, it is possible to dye in any color, but there are problems such as the need for a tow processing machine or an increase in processing loss.

As a method for solving the above-mentioned problems, Patent Document 1 describes a method in which an anionic activator is applied to a shrinkable acrylic fiber and then treated with a dye solution containing a cationic dye at 70 ° C. or lower. Yes. By doing so, the shrinkage of the fiber in the dyeing process can be suppressed, but the dyeing bath is contaminated by the binding of the anionic active agent dropped in the dyeing bath with the cationic dye. The dye bath must be cleaned. In addition, there is a problem in practical use because the fastness to dyeing occurs due to the physical attachment of an anionic active agent and a cationic dye on the fiber.

Further, Patent Document 2 discloses an acrylic short fiber having dry heat shrinkage dyed with a cationic dye, using a fiber obtained by copolymerizing a halogen-containing monomer and a sulfonic acid-containing monomer as a raw fiber. However, the sulfonic acid component present in the center of the fiber is unlikely to contribute to the fixing of the dye, and the amount of sulfonic acid-containing monomer is increased. Connected.
JP 2003-253574 A Republished patent WO2002 / 053825

As described above, the shrinkable acrylic fiber is limited in its usage because it shrinks in the dyeing process. In order to eliminate this inconvenience, various methods such as original deposition, tow dyeing, application of an anionic active agent, and a device for a fiber-constituting polymer have been studied, but all have some problems. The present invention has been made based on the present situation, and provides an acrylic fiber that can be dyed at a temperature lower than the temperature at which shrinkage is fully developed and that can exhibit sufficient shrinkage by heating after dyeing. For the purpose.

As a result of diligent studies to achieve the above-mentioned object, the present inventor has reached the present invention shown below.
(1) Shrinkage rate in hot water of 75 ° C. or less is less than 15%, shrinkage rate in wet heat treatment of 90-100 ° C. or dry heat treatment of 120-150 ° C. is 15% or more, and 75 ° C. A low-temperature dyeable shrinkable acrylic fiber characterized in that it can be dyed as follows.
(2) The low-temperature dyeable shrinkable acrylic fiber according to (1), comprising 1 to 10% by weight of a water-swellable polymer.
(3) The low-temperature dyeable shrinkage according to (2), which is obtained by complex spinning of a spinning stock solution containing a water-swellable polymer and a spinning stock solution not containing a water-swellable polymer Acrylic fiber.
(4) A type in which the water-swellable polymer is selected from the group consisting of polyvinyl cyanoethyl ether, a copolymer of acrylonitrile and methoxypolyethylene glycol methacrylate, polyvinyl alcohol, cyanoethylated polyvinyl alcohol, cyanoethyl cellulose, and methallyl sulfonic acid copolymer The low-temperature dyeable shrinkable acrylic fiber according to (2) or (3), which is the above polymer.

The low-temperature dyeable shrinkable acrylic fiber of the present invention can be dyed at a low temperature of 75 ° C. or lower, not at a high temperature at which the conventional shrinkage is fully manifested in the dyeing process. Shrinkage can be expressed by heat. For this reason, it is not necessary to dye after forming a fiber structure like conventional shrinkable acrylic fibers, and it is sufficient to dye before forming. The number of colors that can be used, or the number of colors as in the case of the original fiber, can be dyed to an arbitrary hue in the same way as normal acrylic fibers. It can be used more freely and in a wider range of applications.

The low-temperature dyeable shrinkable acrylic fiber of the present invention can be dyed at 75 ° C. or lower, preferably 70 ° C. or lower, more preferably 65 ° C. or lower. When a temperature exceeding 75 ° C. is required for dyeing, the shrinkage of the fibers in the dyeing process becomes too large, and sufficient shrinkage cannot be obtained after dyeing. In the present invention, the term “stainable” refers to a state in which a person skilled in the art normally determines that staining is possible. Specifically, in addition to the case where it cannot be dyed at all, the case where the color disappears even after being washed, etc., or when it is dyed only to the extent of contamination, does not fall under “dyeable” in the present invention.

The low-temperature dyeable shrinkable acrylic fiber of the present invention has a shrinkage ratio in hot water of 75 ° C. or lower of less than 15%, preferably less than 12%, more preferably less than 10%. When the shrinkage rate is 15% or more in hot water at 75 ° C. or lower, it is difficult to obtain sufficient shrinkage after dyeing, and uniform shrinkage cannot be obtained.

Moreover, the low-temperature dyeable shrinkable acrylic fiber of the present invention has a shrinkage ratio of 15% or more, preferably 20% or more, more preferably 30 in a wet heat treatment at 90 to 100 ° C. or a dry heat treatment at 120 to 150 ° C. % Or more is desirable. When the shrinkage ratio in the wet heat treatment at 90 to 100 ° C. or the dry heat treatment at 120 to 150 ° C. is less than 15%, it is difficult to obtain sufficient shrinkage after dyeing, and uniform shrinkage cannot be obtained. .

Furthermore, the low temperature dyeable shrinkable acrylic fiber of the present invention is 15% or more with respect to the dyed fiber by performing wet heat treatment at 90 to 100 ° C. or dry heat treatment at 120 to 150 ° C. after dyeing at 75 ° C. or less, It is desirable that the shrinkage rate is preferably 20% or more, more preferably 30% or more.

The acrylonitrile-based polymer constituting the low-temperature dyeable shrinkable acrylic fiber of the present invention may be any one that can be used for producing conventionally known shrinkable acrylic fibers. Representative examples of vinyl monomers copolymerized with acrylonitrile include acrylic acid, methacrylic acid, or esters thereof; acrylamide, methacrylamide, or N-alkyl substituted products thereof; vinyl esters such as vinyl acetate; vinyl chloride , Vinyl halides such as vinyl bromide and vinylidene chloride or vinylidenes; unsaturated sulfonic acids such as vinyl sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, p-styrene sulfonic acid or salts thereof, and acrylonitrile such as their salts can be copolymerized And well-known monomers. In addition, you may use multiple types of acrylonitrile-type polymer as an acrylonitrile-type polymer which comprises the low-temperature dyeable shrinkable acrylic fiber of this invention.

The low-temperature dyeable shrinkable acrylic fiber of the present invention preferably contains 1-10% by weight, more preferably 1-6% by weight, of a water-swellable polymer. The water-swellable polymer absorbs the dye solution even at a low temperature, and the absorbed dye diffuses into the fiber due to the concentration gradient, so that it can be easily dyed even at a low temperature. Moreover, since a hygroscopic property improves by containing a water swellable polymer, the secondary effect of suppressing generation | occurrence | production of static electricity is also acquired.

The water-swellable polymer is usually added by adding to the spinning dope, but if it exceeds 10% by weight, the spinning dope may gel and be unable to be spun. On the other hand, when the content is less than 1% by weight, the amount of the water-swellable polymer is decreased, so that an effect such as easy dyeing at a low temperature may not be obtained. Also, as the amount of water-swellable polymer added increases, nozzle clogging and thread breakage are more likely to occur in the spinning process, and the fiber properties of the resulting fiber tend to decrease. It is desirable to make the addition amount as small as possible while taking the above into consideration. In addition, there exists an advantage of cost suppression in making the addition amount of a water swellable polymer small.

Furthermore, as a result of repeated studies by the present inventor, by using a spinning stock solution containing a water-swellable polymer and a spinning stock solution not containing a water-swellable polymer, composite spinning such as a side-by-side method is performed, and water swelling It is clear that the uneven distribution of the light-sensitive polymer improves the dyeability at low temperatures and facilitates the deep color dyeing compared to the case where the same amount of water-swellable polymer is dispersed throughout the fiber. Became. In addition, the dye saturation value was also greatly improved by using the side-by-side type. If these are grasped conversely, it means that even with a smaller amount of water-swellable polymer, it is possible to express good dyeability, and it is also effective in terms of suppression of deterioration in operability and fiber properties.

The reason for improving the dyeability can be estimated as follows when the side-by-side method is taken as an example. That is, from the viewpoint that the water-swellable polymer absorbs the dye liquor and diffuses the absorbed dye into the fiber, by using a side-by-side type, on the side containing the water-swellable polymer By increasing the concentration of the polymer, more dye liquor is absorbed than when sparsely dispersed. On the other hand, on the side not containing the water-swellable polymer, in addition to the diffusion of the dye from the normal dye bath through the fiber surface, the dye is also diffused through the bonding surface from the side containing the water-swellable polymer that has absorbed a large amount of dye liquor. As a result, the substantial area in contact with the dye liquor increases. As a result, it is considered that the dyeability of the entire fiber may be improved.

The water swelling degree of the water-swellable polymer is preferably 10 to 300 g / g, more preferably 20 to 150 g / g, as obtained by the measurement method described later. When the degree of water swelling exceeds 300 g / g, troubles such as yarn breakage are likely to occur in the spinning process.

The type of water-swellable polymer is not particularly limited, but polyvinyl cyanoethyl ether, a copolymer of acrylonitrile and methoxypolyethylene glycol methacrylate, polyvinyl alcohol, cyanoethylated polyvinyl alcohol, cyanoethyl cellulose, methallyl sulfonic acid copolymer, etc. It can be illustrated. Among these, it is preferable to employ a polymer obtained by copolymerizing 10 to 70% by weight of acrylonitrile and 30 to 90% by weight of methoxypolyethylene glycol methacrylate. These water-swellable polymers may be used alone or in combination.

With respect to the dye used for dyeing the low-temperature dyeable shrinkable acrylic fiber of the present invention, it is possible to use the same dye used for dyeing ordinary acrylic fibers. As for the dyeing conditions, in order to develop sufficient shrinkage after dyeing, the dyeing bath temperature is 75 ° C. or lower. However, for other conditions, conditions for dyeing normal acrylic fibers can be adopted. The low-temperature dyeable shrinkable acrylic fiber of the present invention can naturally be dyed even at a temperature of 75 ° C. or higher, but there is a risk that sufficient shrinkage after dyeing cannot be obtained.

As one specific example of the low-temperature dyeable shrinkable acrylic fiber of the present invention described above, acrylonitrile 75 to 95% by weight, sodium methallylsulfonate 0 to 3% by weight, and vinyl acetate 5 to 22% by weight are copolymerized. 90% by weight or more of the obtained polymer and 10% by weight or less of a copolymer of acrylonitrile and methoxypolyethylene glycol methacrylate were mixed with a sodium thiocyanate aqueous solution to form a spinning stock solution. The spinning stock solution was made of a known shrinkable acrylic fiber. Mention may be made of fibers obtained by spinning according to the production method.

Examples are shown below for facilitating the understanding of the present invention. However, these are merely examples, and the gist of the present invention is not limited thereto. In the examples, parts and percentages are based on weight unless otherwise specified. Further, the degree of water swelling, shrinkage, dyeability, dye saturation value, and dye fastness described in the examples are measured by the following methods.

(1) Degree of water swelling After the water dispersion of a sample polymer is placed in a 100 ° C hot air dryer to remove moisture (the sample polymer may be in the form of a film), the sample polymer is kept constant in a vacuum dryer at 80 ° C. Dry until measured and measure weight (W0). Next, the sample polymer is immersed in water and after 24 hours at 25 ° C., the sample polymer in a water swollen state is sandwiched between filter papers to remove excess water, and the weight (W1) at the time of water swelling is measured. From the above results, the degree of water swelling is calculated according to the following formula.
Water swelling degree (g / g) = (W1-W0) / W0

(2) Shrinkage ratio After measuring the fiber length (L1) of the sample fiber, the fiber length (L2) after shrinkage is measured by shrinking in 75 ° C water for 60 minutes or 130 ° C with dry heat for 5 minutes. In addition, the measurement is performed by applying a load according to the measurement method described in JIS L-1015. From the above results, the shrinkage rate is calculated according to the following equation.
Shrinkage rate (%) = (L1-L2) / L1 × 100

(3) The dyeable sample fiber was cut to a fixed length of 51 mm, and immersed in a dyeing bath containing the cationic dye Malachite Green 2% omf (% omf is a percentage of the fiber mass) and acetic acid 2% omf at 75 ° C. for 60 minutes. , Soaping, washing and drying. The obtained fiber is visually evaluated for dyeability based on the following criteria.
○: Fully dyeable △: Lightly dyeable ×: Little dye

(4) Dye saturation value 0.1 g of the fiber obtained in the above (3) is dissolved in 25 ml of γ-butyrolactone, and the absorbance (A) is measured with a spectrophotometer. On the other hand, 0.1 g of acrylic fiber completely absorbed with Malachite Green 1% omf by boiling is dissolved in 25 ml of γ-butyrolactone, and the absorbance (B) is measured with a spectrophotometer. From the above results, the dye saturation value is calculated according to the following formula.
Dye saturation value (% omf) = A / B

(5) Dye fastness (fastness to light dyeing)
About the fiber obtained by said (3), based on JISL-0842 (3rd exposure method), it tests by setting the temperature of a black panel thermometer to 63 +/- 3 degreeC, and determines the grade of discoloration. In addition, Suga Test Instruments Co., Ltd. Standard UV Long Life Fade Mater was used for the measuring apparatus. The light fastness to light dyeing can be practically used if it is grade 3 or higher.

[Production of acrylonitrile-based polymer and water-swellable polymer]
Aqueous suspension polymerization was carried out with the composition shown in Table 1 to prepare acrylonitrile-based polymers A and B and water-swellable polymers a, b and c. The abbreviations in the table represent AN: acrylonitrile, MA: methyl acrylate, SMAS: sodium methallylsulfonate, VAc: vinyl acetate, MPEGMA: methoxypolyethylene glycol (30 mol) methacrylate. Moreover, about the water-swellable polymer, the water swelling degree calculated | required from the said measuring method was written together.

[Examples 1 to 4, Comparative Example 1]
A spinning stock solution X was prepared by dissolving acrylonitrile-based polymer A at a ratio shown in Table 2 with respect to 900 parts of 50% aqueous sodium rhodate solution and then adding and mixing water-swellable polymer a dispersed in water. . Separately from this, 100 parts of acrylonitrile-based polymer A was dissolved in 900 parts of 50% aqueous sodium rhodate solution to prepare a spinning dope Y. The prepared spinning solutions X and Y are subjected to composite spinning in accordance with a normal shrinkable acrylic fiber manufacturing method with an X / Y ratio of 50/50 through a normal side-by-side composite fiber spinneret. The fibers of Examples 1 to 4 were created. Moreover, the fiber which did not add the water swellable polymer as the comparative example 1 was also created. Table 2 shows the results of evaluating the shrinkage, dyeability, dye saturation value, and dye fastness of the fibers obtained.

As can be seen from Table 2, in Examples 1 to 3, shrinkable acrylic fibers that were sufficiently dyeable even at 75 ° C. and had sufficient dyeing fastness were obtained. In Example 4, although the addition amount of the water-swellable polymer was low, it was possible to dye it lightly. In contrast, Comparative Example 1 could hardly be dyed at 75 ° C.

[Examples 5 to 7, Comparative Example 2]
After dissolving acrylonitrile-based polymer B at a ratio shown in Table 3 with respect to 900 parts of 50% aqueous sodium rhodanate solution, a spinning dope was prepared by adding and mixing a water-swellable polymer dispersed in water. The obtained spinning dope was spun in accordance with a normal method for producing shrinkable acrylic fibers. Table 3 shows the results of evaluating the shrinkage, dyeability, dye saturation value, and dye fastness of the fibers obtained.

As can be seen from Table 3, in Examples 5 to 7, shrinkable acrylic fibers that can be dyed even at 75 ° C. and have sufficient dyeing fastness were obtained. When these Examples are compared, it is considered that the higher the water swelling degree of the water-swellable polymer added, the higher the dye saturation value, and the higher the dyeability. Further, in Examples 5 to 7, the water-swellable polymer is dispersed throughout the fiber, but compared to the side-by-side Examples 1 to 4, the dye saturation value relative to the added amount of the water-swellable polymer It is considered that the distribution of the water-swellable polymer is biased and contributes to the improvement of the dyeability. In Example 5, although some yarn breakage occurred in the spinning process, it was possible to obtain fibers. However, in Comparative Example 2, since the amount of the water-swellable polymer added was too large, the spinning dope gelled and could not be spun.

The low-temperature dyeable shrinkable acrylic fiber of the present invention has a practical hue even when dyeing at low temperatures and can exhibit sufficient shrinkage even after dyeing, and is dyed with raw cotton such as sliver knit. Ideal for use.

Claims (4)

Shrinkage in hot water at 75 ° C. or less is less than 15%, shrinkage in wet heat treatment at 90 to 100 ° C. or dry heat treatment at 120 to 150 ° C. is 15% or more, and dyeing at 75 ° C. or less A low temperature dyeable shrinkable acrylic fiber characterized in that it is possible. 2. The low-temperature dyeable shrinkable acrylic fiber according to claim 1, comprising 1 to 10% by weight of a water-swellable polymer. 3. The low-temperature dyeable shrinkable acrylic fiber according to claim 2, wherein the low-temperature dyeable shrinkable acrylic fiber is obtained by complex spinning a spinning stock solution containing a water-swellable polymer and a spinning stock solution not containing a water-swellable polymer. The water-swellable polymer is one or more polymers selected from the group consisting of polyvinyl cyanoethyl ether, a copolymer of acrylonitrile and methoxypolyethylene glycol methacrylate, polyvinyl alcohol, cyanoethylated polyvinyl alcohol, cyanoethyl cellulose, and methallyl sulfonic acid copolymer. The low-temperature dyeable shrinkable acrylic fiber according to claim 2 or 3, wherein