JP5207809B2 - Split type composite fiber, fiber structure using the same, and wiping cloth - Google Patents

Description

  The present invention relates to a split type composite fiber that is suitable for performing with high accuracy without damaging a target part when a cleaning tool such as a wiping cloth or a precision machine such as a hard disk is polished or cleaned.

  Conventionally, high-density and bulky fabrics have been demanded and studied in various fields such as washing cloth use and clothing use. Such cloths are used for cleaning cloths such as general cleaning uses such as wiping glasses and washing face; polishing of electronic parts such as hard disks, and cleaning equipments in the manufacturing process of hard disks. Is used.

  Among these applications, in applications where electronic parts are polished, a non-woven fabric such as polyester is used as a base fabric, and artificial leather impregnated on the surface with a urethane resin or the like or a composite fiber such as polyester and polyamide is formed into a fabric. A polishing cloth or the like that has been divided into microfibers later is used.

  For example, the capacity of hard disks and the like has been increasing in recent years, and products of 100 GB or more are common. At the same time, the miniaturization of the hard disk has progressed remarkably, and in order to satisfy both the large capacity and the miniaturization at the same time, it is necessary to precisely polish the disk surface.

  In response to this requirement, split type composite fibers made of polyamide and polyester can be split into both components by physical and chemical treatment, and the resulting microfibers are inexpensive and have performance suitable for precise polishing. Have. For example, Patent Document 1 proposes a wiping cloth suitable for polishing a hard disk with a specific number of drives and a cover factor after densifying polyester / polyamide composite fibers after splitting.

  For example, Patent Document 2, Patent Document 3, and Patent Document 4 disclose a method for dividing a split-type composite fiber by means of polyamide swelling / shrinking. In particular, the invention of Patent Document 3 describes that the fiber structure is densified by increasing the swelling / shrinkage of polyamide.

JP 2000-303300 A Japanese Examined Patent Publication No. 53-35633 Japanese Patent Publication No. 61-37383 JP-A-4-272223

  However, when the polyamide to be used is a normal one, there is a limit to the swelling and shrinkage of the polyamide unless the special treatment agent that swells and shrinks the polyamide, such as benzyl alcohol, is sufficient. Not something. Further, the denseness and bulkiness of the resulting fiber structure may not be able to cope with a higher level of wiping performance that has recently been required.

  In the partitioning method by swelling / shrinking of polyamide with a treatment agent such as benzyl alcohol, the self-dusting fine particles precipitated mainly due to the dissolution of oligomers contained in the polyester are generated. Will affect the productivity. Therefore, there is a strong demand for reduction of self-dusting fine particles generated from the fiber material itself of the polishing cloth or wiping cleaning tool, low molecular weight substances extracted by a solvent, and the like.

  Furthermore, the split type composite fibers used in these materials are usually used as a matting agent used in general-purpose polyester fibers and polyamide fibers, as a raw material, a resin containing at least a white pigment such as titanium dioxide. When the hard disk is polished precisely, the titanium dioxide may damage the hard disk surface.

  Therefore, the present invention solves the above-mentioned problems, and when it is used as a wiping cloth for polishing an abrasive cloth such as a hard disk or cleaning an electronic device, it is self-generated from an oligomer or the like. To obtain split-type composite fibers, woven and knitted fabrics, and wiping cloths that are suitable for polishing and cleaning with little generation of low molecular weight substances extracted by dust particles, solvents, etc., and without damaging the hard disk surface or precision electronic components. Objective.

To achieve the above object, the present invention provides a polyamide resin composition comprising an aromatic polyamide and an aliphatic polyamide that does not contain a white pigment, and a polyester resin that has no affinity for the polyamide resin composition and does not contain a white pigment. Tona is, aromatic polyamide consists of split type composite fiber is a polyamide and an aliphatic dicarboxylic acid and an aromatic diamine as a main structural unit, the gist of the wiping cloth composed of the fiber structure is a woven or knitted fabric And

  As a preferred embodiment of the present invention, the aromatic polyamide is a polyamide having an aliphatic dicarboxylic acid and an aromatic diamine as main structural units.

  Preferred embodiments of the present invention include those in which the aromatic polyamide is a resin (nylon MXD6 polymer) obtained from metaxylylenediamine and adipic acid, and the aliphatic polyamide is a resin (nylon 6) obtained from ε-caprolactam.

  As a more preferred embodiment of the present invention, there may be mentioned one in which the weight mixing ratio of the polyamide component nylon MXD6 and nylon 6 is 35:65 to 70:30. As a particularly preferred embodiment, a polyamide component having a weight mixing ratio of nylon MXD6 and nylon 6 of 45:55 to 55:45 can be mentioned.

  This invention is also a fiber structure which consists of the said split type composite fiber. The fiber structure is preferably a woven fabric or a knitted fabric. The present invention is also a wiping cloth made of the above-mentioned split type composite fiber.

  The present invention also includes a step (1) of producing a fiber structure using the above-described split type composite fiber, and a split type composite by subjecting the fiber structure obtained by the step (1) to an alkali dissolution treatment. It is also a manufacturing method of a fiber structure characterized by comprising a step of splitting fibers. The method for manufacturing a fiber structure may further be a method for manufacturing a fiber structure having a step (3) of heat-treating the woven or knitted fabric obtained by the above-described steps. Furthermore, it is also a method for manufacturing a wiping cloth in which these woven or knitted fabrics are cut into a desired size and washed with pure water.

Since the split-type conjugate fiber of the present invention uses a polyamide resin composition of an aromatic polyamide and an aliphatic polyamide as the polyamide component, the shrinkage performance of the polyamide component is large.
Conventional benzyl alcohol treatment divides a polyamide into a plurality of components by swelling and shrinking the polyamide, but the split type conjugate fiber of the present invention uses a polyamide component having a large shrinkage performance, and thus is usually performed in a general processing step. Sufficient shrinkage performance can be obtained under the heating conditions for weight reduction with an aqueous alkaline solution. The resulting fiber structure is dense and bulky and has a wiping performance suitable for polishing a hard disk. Further, since it does not contain a white pigment, it prevents the parts to be polished from being damaged when polishing a precision machine such as a hard disk.

  In the present invention, a polyester resin is used as a fiber-forming polymer having no affinity with the polyamide resin composition. If it is a polyester resin, a part of the polyester component is dissolved by applying a weight reduction process with an alkaline aqueous solution, which is usually performed in a general processing step, and the heated alkaline aqueous solution sufficiently heats the polyamide component. A good shrinkage performance. In addition, since the self-dusting fine particles and low molecular weight substances precipitated by the elution of oligomers mainly contained in the polyester are dissolved and removed by the alkaline aqueous solution, the number of self-dusting particles in the product can be reduced.

Hereinafter, the present invention will be described in detail.
First, the split type composite fiber of the present invention is composed of a polyamide resin composition and a polyester resin.
The polyamide resin composition is composed of an aromatic polyamide and an aliphatic polyamide.
Since the polyamide resin composition comprising this combination has high shrinkage performance, it exhibits good splitting properties even with a treatment agent other than low-concentration benzyl alcohol or alcohol having no swelling action (for example, alkali dissolution treatment, hot water treatment). . And since the fiber structure after a process is rich in denseness and bulkiness, it has the wiping performance suitable for grinding | polishing and cleaning of a hard disk etc. On the other hand, when the polyamide component is only aromatic polyamide or only aliphatic polyamide, good wiping performance cannot be obtained because the shrinkage performance is small. Furthermore, since the shrinkage performance is high, high shrinkage is obtained. On the other hand, since the polyamide resin composition is used in combination with a polyester resin which is not as high in shrinkage performance, the denseness due to the high shrinkage rate is obtained. And bulkiness can also be obtained.

  Examples of the aliphatic polyamide include known fiber-forming polyamides, and specific examples include nylon 6, nylon 66, nylon 4, and the like. The molecular weight of the polyamide is not particularly limited as long as fiber formation is possible. Nylon 6 is produced in large quantities and is advantageous in terms of cost, and is preferably used in the present invention.

  The aromatic polyamide is preferably a polyamide having an aliphatic dicarboxylic acid and an aromatic diamine as main structural units. Since such an aromatic polyamide has a higher shrinkage performance, the fiber structure obtained after the split fiber treatment can obtain denseness and bulkiness. Examples of such an aromatic polyamide include a resin (nylon MXD6 polymer) obtained from metaxylylenediamine and adipic acid. Among these, nylon MXD6 polymer is preferable from the viewpoint of shrinkage performance.

  In the polyamide resin composition of the present invention, it is particularly preferable that the aromatic polyamide is nylon MXD6 polymer and the aliphatic polyamide is nylon 6. Since this has particularly high shrinkage performance, the fiber structure obtained after splitting treatment can obtain particularly good wiping performance. In this case, the weight mixing ratio of nylon MXD6 and nylon 6 is more preferably 35:65 to 70:30, and particularly preferably 45:55 to 55:45.

  The aromatic polyamide and the aliphatic polyamide are preferably those in which the aliphatic polyamide has a higher viscosity. Although the cause is unknown, better shrinkage performance can be obtained by doing so. More specifically, it is preferred that the aliphatic polyamide has a high viscosity when the difference in relative viscosity at 25 ° C. measured using 95.8% concentrated sulfuric acid as a solvent is 0.2 or more and 0.4 or less.

  The split type composite fiber of the present invention comprises the above polyamide resin composition and a polyester resin. The split type composite fiber combining these is split by dissolving a part of the polyester when the polyamide resin composition is subjected to alkali dissolution processing. Furthermore, the polyamide resin is sufficiently contracted by being heated by such an alkali dissolution processing step or by a heat treatment that is performed separately, whereby a high-density and bulky fiber structure can be obtained. Such a fiber structure can obtain excellent wiping properties. Further, since the self-dusting fine particles and low molecular weight substances mainly derived from the oligomers contained in the polyester are dissolved and removed by the alkaline aqueous solution, the number of self-dusting particles in the product can be reduced.

  Furthermore, it has the advantage that it can be split without any treatment with benzyl alcohol. That is, since the conjugate fiber of the present invention has a high shrinkage performance of the polyamide component, it can be split efficiently, and for this reason, a good splitting can be performed without performing the benzyl alcohol treatment performed in ordinary splitting fibers. It also has the advantage that fineness can be obtained.

  Examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene oxybenzoate, poly 1,4-dimethylcyclohexane terephthalate, and a copolyester containing them as a main component. Other polymers can also be used as appropriate. From the viewpoint of versatility and fiber properties, polyethylene terephthalate is preferable.

  The polyamide resin composition and the polyester resin do not contain a white pigment. Here, the meaning of not containing a white pigment is that the white pigment such as titanium dioxide which is usually added in order to suppress the gloss of the yarn or improve the spinning operability is not actively added. There may be a small amount of contamination due to contamination in manufacturing and processing processes. Even in such a case, if the analysis value by a general ash content measurement method is less than 50 ppm in the polymer, it is preferable that the surface is not damaged at the time of hard disk polishing and cleaning.

  The fineness of the split-type conjugate fiber of the present invention is not particularly limited, and can be appropriately determined within a range where spinning is possible. From the viewpoint of the shrinkage performance of the fiber that affects the wiping performance of the product, the total fineness of the warp and the weft is preferably 30 to 300 dtex. More preferably, it is 40-200 dtex, Most preferably, it is 50-150 dtex. However, when the fineness is too small, the shrinkage performance as a yarn is low, and therefore it is preferable to have a fineness that can sufficiently shrink.

  In addition, the single yarn fineness of the split type composite fiber of the present invention may be any, but at least a part, preferably all, of the components after split splitting are ultrafine fibers having a fineness of 0.5 dtex or less. If so, the obtained fiber structure is more excellent in flexibility and denseness, and is suitable for polishing performance and cleaning performance.

  The cross-sectional shape of the split-type composite fiber of the present invention is such that the polyamide resin composition and the polyester resin are in a cross section of a single fiber, and one component does not completely contain the other component, The shape is preferably joined along the longitudinal direction. Specifically, a side-by-side split-type composite fiber as shown in FIG. 1, a side-by-side repeat-type split-type composite fiber as shown in FIG. 2, and a radiation joined in a shape complementary to the radial shape and radial shape as shown in FIGS. Examples include mold split type composite fibers, hollow annular type split type composite fibers as shown in FIG.

  As the wiping cloth, a radial split type composite fiber or a hollow annular type composite fiber is preferably used. In particular, in the split type composite fiber of nylon MX polymer and aliphatic polyamide and polyester, the radial split type composite fiber is divided into a large number of radial parts such as 8 or more by the radial part of FIG. Even without using a swelling agent such as benzyl alcohol, it can be split and shrunk by alkali dissolution treatment and heat treatment, so polyester impurities can be removed, self-dusting and residual ions are low, and cleaning performance is excellent. It will be.

  As a split fiber processing method of the split type composite fiber of the present invention, there is a method by alkali dissolution. In this method, the split type composite fiber of the present invention is immersed in a heated alkaline aqueous solution, a part of the polyester is dissolved, and at the same time, the polyamide component is contracted to split the fiber. At this time, since the self-dusting fine particles and low molecular weight substances mainly derived from oligomers contained in the polyester resin are dissolved and removed by the alkaline aqueous solution, the number of self-dusting particles in the product can be reduced.

  The conditions for the treatment by alkali dissolution are generally the methods implemented in the weight loss processing of the polyester fiber structure, for example, a method using a 0.5% to 5.0% sodium hydroxide aqueous solution. Can do. More preferably, it is 1.0% to 3.0%, and particularly preferably 1.0% to 2.0%. The treatment temperature is preferably 85 ° C to 100 ° C, more preferably 90 ° C to 98 ° C.

  The fiber structure of the present invention is composed of the above-described split type composite fiber. Examples of the fiber structure include yarns, yarn bundles, woven fabrics, knitted fabrics, and non-woven fabrics. Among them, woven fabrics or knitted fabrics are preferable. The fiber structure of the present invention, after producing a fiber structure from the above-described split-type composite fiber, splits the split-type composite fiber by performing the above-described treatment, and further performs heat treatment or the like as necessary. It is preferable that it is obtained by performing.

  When the fiber structure of the present invention is a woven fabric, examples of the woven structure include plain weave, satin weave, and oblique weave. A satin weave is preferable because a denser fabric can be obtained. Moreover, when using as a wiping cloth, for example, plain weave, satin weave, and oblique weave are preferable.

  In the fiber structure of the present invention, all of the constituent fibers may be composed of the above-mentioned split-type composite fibers, or may be fibers using fibers other than the above-mentioned split-type composite fibers at a ratio of 30% or less. Good.

  The suitable finishing cover factor when using the textile structure of this invention which is a textile fabric as a wiping cloth used in a clean room is illustrated. In the case of plain weave, warp 1000 or more and weft 800 or more are preferable, and in the case of satin weave, warp 1500 or more and weft 1000 or more are preferable.

  When the split type composite fiber of the present invention is used, there is also an advantage that a fiber structure having the above-described high cover factor can be obtained. That is, as described above, high shrinkability can be obtained by using a polyamide resin composition composed of an aromatic polyamide and an aliphatic polyamide as the polyamide resin. Therefore, the cover factor can be obtained by shrinking the fiber structure by performing heat treatment after splitting the fiber structure. When the fiber structure thus contracted is a woven or knitted fabric, the surface is in a state of polyester and inside is polyamide.

  When the fiber structure of the present invention is a knitted fabric, it may be either a warp knitting or a weft knitting. Specifically, a weft knitting structure is preferable, and when used as a wiping cloth, for example, an interlock structure is preferable. When the fiber structure of the present invention which is a knitted fabric is used as a wiping cloth used in a clean room, for example, the number of wales is preferably 70 to 100 / inch and the number of courses is 70 to 100 / inch. In the case of tricot, it is preferable to use about 28G. In addition, the split type fibers may be used for all of the front yarn, the back yarn, and the middle yarn, or only a part of the split yarns may be used, but at least the front yarn and the back yarn are used. It is more preferable.

  The fiber structure of the present invention can be used as a wiping cloth. The wiping cloth of the present invention has excellent wiping performance even in the use of precision equipment in a clean room, such as for use in manufacturing processes of hard disks and the like. Moreover, it can be cut into a predetermined size and shape such as a string shape, a tape shape, and a square shape.

Next, the manufacturing method of the split type composite fiber of this invention is demonstrated concretely.
First, the aromatic polyamide and the aliphatic polyamide are prepared. These are mixed to produce a polyamide resin composition. Although this mixing method is not particularly limited, for example, these chips can be stirred or kneaded in a container.

  Then, the obtained polyamide resin composition and the polyester resin are spun and stretched by drawing or the like. In addition, the spinning method and the twisting method are not particularly limited, and a method of stretching after spinning by a conventional method, a direct spinning method, and the like can be appropriately determined. Further, the stretching method is not particularly limited, and can be appropriately determined such as single-stage stretching or multi-stage stretching.

  The spinning conditions can be appropriately determined from the viewpoint of the relative viscosity of the polymer and operability. For example, as a polyamide component, a nylon 6 polymer having a relative viscosity of 2.0 to 3.0 and a nylon MXD6 polymer having a relative viscosity of about 2.7 are mixed to produce a polymer resin composition. Subsequently, using polyethylene terephthalate having an intrinsic viscosity of 0.6 to 0.7 as polyester, melt spinning is performed by a conventional method to obtain an undrawn yarn. In this case, the extrusion temperature is preferably 280 to 295 ° C, particularly preferably 283 to 292 ° C. The spinning winding speed is preferably 500 to 2,000 m / min, particularly preferably 800 to 1,700 m / min.

  Note that there are no particular limitations on the condition of the twisting after winding by the conventional method. One-stage stretching, multi-stage stretching, roller heater / roller heater stretching, roller heater / plate heater stretching, and the like can be appropriately determined.

  For example, when unstretched yarn obtained by melt spinning in the above-described conventional method is used, if a roller heater and a plate heater are used, the roller heater is preferably 60 ° C to 90 ° C, particularly 70 ° C to 85 ° C. preferable. The plate heater is preferably from 130 ° C to 170 ° C, particularly preferably from 145 ° C to 160 ° C.

  The draw ratio is preferably set according to the spinning speed. By determining the spinning speed and the draw ratio in a well-balanced manner, the strength and elongation of the obtained fiber can be adjusted, and a fiber excellent in weaving property can be obtained. For example, when the spinning speed is 1,500 m / min, the draw ratio is preferably 2.0 times to 2.4 times, and particularly preferably 2.1 times to 2.3 times.

  The stretching speed is preferably 500 to 1,000 m / min, and particularly preferably 600 to 900 m / min from the viewpoint of operability. Further, it is preferable to set the spindle rotation speed (rpm) to a value corresponding to the stretching speed. By appropriately determining the number of spindle rotations corresponding to the stretching speed, an appropriate number of twists can be obtained, and good operability and good shrinkage performance can be obtained.

  Next, an example of manufacturing a wiping cloth using the split type composite fiber is shown below.

  First, a fiber structure is manufactured using the split type composite fiber (step (1)). The step (1) is not specifically limited, and the fiber structure may be produced by a normal method.

  The fiber structure obtained by the above step (1) is split (step (2)). A preferred method for splitting treatment is a method of dissolving in alkali.

  In the case of the method of dissolving in an alkali, as described above, the split type composite fiber of the present invention is immersed in a heated aqueous alkali solution to dissolve a part of the polyester and simultaneously shrink the polyamide component. The self-dusting fine particles and low molecular weight substances derived from the oligomers and the like are dissolved and removed by the aqueous alkali solution, and the number of self-dusting particles in the product can be reduced.

  As described above, the conditions for the treatment by alkali dissolution may be the method generally used in the weight loss processing of the polyester fiber structure, for example, using 0.5% to 5.0% sodium hydroxide aqueous solution. . More preferably, it is 1.0% to 3.0%, and particularly preferably 1.0% to 2.0%. The treatment temperature is preferably 85 ° C to 100 ° C, more preferably 90 ° C to 98 ° C.

  Furthermore, it is preferable to heat-treat the fiber structure obtained by the above step (2) (step (3)). Fibers can be shrunk by such heat treatment, and the woven fabric can be densified. The heat treatment can be performed, for example, at 120 to 150 ° C. under wet heat conditions for about 0.5 to 1 hour, and at 150 to 190 ° C. for about 30 seconds to 1 minute under dry heat conditions. be able to. The heat treatment in the above step (3) may be performed simultaneously with the dyeing treatment. That is, the fiber may be contracted by heat treatment for dyeing.

In the method for producing a wiping cloth of the present invention, a knitted fabric is knitted in a width direction of 20 to 40% in a woven fabric by performing the above-described processes on the raw machine obtained through the processes of weaving and knitting. In the method, it is preferable that the final fiber structure is obtained by shrinking in the width direction of 40 to 60%. By obtaining such a shrinkage rate, it is preferable in terms of obtaining excellent wiping properties. The shrinkage rate is the width in the state of the living machine as W0, the length as L0, the width after shrinkage as W, and the length as L.
100 × {[((W0−W) / (W0)} (%)
It can be calculated by the following formula.

  And, when used for polishing and cleaning of precision electronic equipment such as hard disks used in a clean room, then the resulting fabric is washed with pure water in a clean room and dried, if necessary, If necessary, cut into a desired size. Then, if necessary, it can be washed with pure water in a clean room and dried to obtain a wiping cloth. The obtained wiping cloth may be sealed in a resin film. When this sealed pack is used for manufacturing a hard disk or the like, it can be opened and a wiping cloth can be used.

  A fiber structure such as a woven or knitted fabric using the split composite fiber of the present invention has a raised feeling suitable for polishing and cleaning. In addition, the number of self-dusting fine particles and low molecular weight substances is small, and precision parts are not contaminated. In the case of a polishing fabric, the above-mentioned fiber structure can be cut into an appropriate tape to obtain a texture tape, and the obtained texture tape can reduce damage to the parts to be polished.

  Hereinafter, the present invention will be described in detail with reference to examples. In addition, this invention is not limited to the Example described below.

A. Intrinsic Viscosity of Polyester The intrinsic viscosity [η] was measured by an ordinary method using an automatic viscometer at 20 ° C. in a mixed solvent of phenol / tetrachloroethane = 6/4 (weight ratio).

B. Relative viscosity of polyamide Relative viscosity ηrel was measured by an ordinary method using an Oswald viscometer at 20 ° C. in a sulfuric acid solvent.

C. Wiping cloth performance After knitting a tubular knitting using split-type composite fibers, each of which was subjected to split fiber treatment, the area shrinkage (%) of the tubular knitted fabric before and after the treatment was measured. Generally, if the area shrinkage (%) is not 30% or more, the wiping performance is insufficient.

D. Self-dusting fine particle count The self-dusting fine particle count was measured according to IES-RP-CC003.2 (Helmke drum method) using a particle counter (KM-27) manufactured by RION.
Note that the sample used for the measurement was washed with ultrapure water in order to reduce factors other than self-dusting.

Example 1
A polyamide resin composition in which a nylon MXD6 (manufactured by Mitsubishi Gas Chemical Co., Ltd., polyamide MXD6 resin) and a nylon 6 having a relative viscosity of 2.6 are mixed at a weight ratio of 50:50 and does not contain a white pigment. Ingredients. On the other hand, polyethylene terephthalate having an intrinsic viscosity of 0.61 is used as component B.
A component: B component is a volume ratio of 1: 2, a spinning temperature of 295 ° C., a spinning speed of 1050 m / min, melt compound spinning so that the A component forms a radial portion, An undrawn yarn was obtained. The obtained undrawn yarn was drawn at a roller heater of 85 ° C., a plate heater of 150 ° C., and a draw ratio of 3.0 times to obtain a 56 dtex / 25 f split type composite fiber.
And using this drawn yarn, a tubular knitted fabric was obtained by a tubular knitting machine having a 28 gauge and a diameter of 10 cm. The obtained cylindrical knitted fabric was immersed in a 2% aqueous sodium hydroxide solution at 95 ° C. for 30 minutes and washed with water to perform division and shrinkage treatment.
In order to evaluate the wiping performance of the obtained tubular knitted fabric, the area of the tubular knitted fabric before and after the division and shrinkage treatment was measured, and the area shrinkage rate (%) was calculated. A very high shrinkage rate of 42.6% was obtained.
Further, the number of self-dusting fine particles having a size of 0.3 μm or more in the obtained cylindrical knitted fabric was measured.
The total number was 14 and very small.
Further, with the obtained tubular knitted fabric, the surface of the hard disk was actually rubbed to confirm the degree of scratching on the surface. The surface was hardly damaged.

(Comparative Example 1)
A fiber was produced by the method described in Example 1 except that the component A was only 6 nylon having a relative viscosity of 2.6, and various evaluations were performed. The results are shown in Table 1.

(Comparative Example 2)
A fiber was produced by the method described in Comparative Example 1, and the splitting and shrinking method of the tubular knitted fabric was made by using 15% by weight of benzyl alcohol and 0.5% by weight of Sunmol BK-Conc (active agent, manufactured by Nikka Chemical Co., Ltd.) Various evaluations were performed as a method of immersing in an emulsified aqueous solution consisting of 10 minutes at 40 ° C. The results are shown in Table 1.

(Comparative Example 3)
A component is a polyamide resin composition in which nylon MXD6 having a relative viscosity of 2.7 and nylon 6 having a relative viscosity of 3.0 containing 2000 ppm of titanium dioxide are mixed at a weight ratio of 50:50, and B component contains 320 ppm of titanium dioxide. A fiber was produced by the method described in Example 1 except that polyethylene terephthalate having an intrinsic viscosity of 0.63 was used, and various evaluations were performed. The results are shown in Table 1.

  Moreover, when the hard disk was grind | polished using the obtained cylindrical knitted fabric and the grinding | polishing surface was observed with the microscope, the thing of Example 1 was flawlessly polished and there was no adhesion of a foreign material. The product of the example was polished more finely than those of Comparative Examples 1 and 2.

  Next, after preparing a glass plate and applying a certain amount of petrolatum on its surface, the glass surface was wiped a certain number of times with the obtained tubular knitted fabric, and the degree of petrolatum removal was observed. As in Example 1 and Comparative Example 2, petrolatum was inflated cleanly, but Comparative Example 1 was inferior in wiping property as compared with Example 1.

(Example 2)
The warp yarn is 84 dtex / 36 f polyester multifilament (S twist: 200 T / m), and the weft yarn is two 56 dex / 25 f split-type composite fiber multifilaments, aligned in the S direction to 110 T / m. A twisted one was prepared. A raw machine was obtained by weaving 5 sheets of satin at a warp density of 140 / 2.54 cm and a weft density of 91 / 2.54 cm.
After the obtained raw machine was scoured, it was immersed in a 2% aqueous sodium hydroxide solution at 95 ° C. for 30 minutes to split the split type composite fiber. Then, the split-type composite fiber was shrunk by liquid dyeing at 130 ° C. for 30 minutes. The warp density of the obtained woven fabric was 192 pieces / 2.54 cm, and the weft density was 95 pieces / 2.54 cm. Here, the area shrinkage ratio between the raw machine and the obtained woven fabric was 35%.
The obtained woven fabric was washed with ultrapure water in a clean room and dried. After cutting into a desired size, it was washed with ultrapure water and dried to obtain a clean room wiping cloth.

(Comparative Example 4)
A raw machine was obtained in the same manner as in Example 2 except that the component A was only nylon 6 having a relative viscosity of 2.6. The resulting raw machine was treated with an emulsified aqueous solution consisting of 35% by weight of benzyl alcohol and 5% by weight of KM-300 (active agent, manufactured by Takemoto Yushi Co., Ltd.) after padding, and the split type composite fiber was split and shrunk. . The warp density of the obtained woven fabric was 192 pieces / 2.54 cm, and the weft density was 95 pieces / 2.54 cm. Here, the area shrinkage ratio between the raw machine and the obtained woven fabric was 35%. Using the resulting woven fabric, a wiping cloth was obtained in the same manner as in Example 2.

In addition, the area shrinkage rate was calculated by the following formula, assuming that the width in the state of the living machine is W0, the length is L0, the width after shrinkage is W, and the length is L.
Area shrinkage (%) = 100 × {[(W0 × L0) − (W × L)] / (W0 × L0)}

(Cleaning performance)
Next, after preparing a glass plate and applying a certain amount of petrolatum on its surface, the glass surface was wiped a certain number of times with the obtained tubular knitted fabric, and the degree of petrolatum removal was observed. The results are shown in Table 2.
(Self dust generation)
In addition, the number of self-generated particles was measured using a particle counter (KM-27) manufactured by RION according to IES-RP-CC003.2 (Helmke drum method). The results are shown in Table 2.
(Residual ions)
Further, residual ions were measured by an ion chromatograph (ICS1500) manufactured by DIONEX. The results are shown in Table 2.

  Comparing Example 2 with that of Comparative Example 4, Example 2 was self-developed while having cleaning performance equivalent to that of Comparative Example 4 in which benzyl alcohol was opened using conventional nylon 6 as polyamide. The number of dust was small and there were few residual ions. It can be suitably used as a wiping cloth for a clean room.

  The fabric produced from the conjugate fiber of the present invention is particularly suitable for industrial materials as a wiping cloth.

It is an example (side-by-side type) fiber cross-sectional view of the split-type conjugate fiber of the present invention. It is an example (side-by-side repeat type) of the fiber cross-sectional view of the split-type composite fiber of this invention. It is an example (radiation type) of the fiber cross-sectional view of the split-type composite fiber of this invention. It is an example (radiation type) of the fiber cross-sectional view of the split-type composite fiber of this invention. It is an example (hollow annular type) of the fiber cross-sectional view of the split type composite fiber of the present invention.

Explanation of symbols

1: Polyamide resin composition component 2: Polyester resin component

Claims (4)

Does not contain a white pigment, Ri Do aromatic polyamide and an aliphatic polyamide and polyamide resin composition and the polyamide resin composition and the polyester resin affinity does not contain a white pigment without consisting, aromatic polyamide, aliphatic dicarboxylic consisting split type composite fiber is a polyamide the acid and an aromatic diamine as a main structural unit, wiping cloth composed of the fiber structure is woven or knitted. The wiping cloth according to claim 1, wherein the aromatic polyamide is a resin (nylon MXD6 polymer) obtained from metaxylylenediamine and adipic acid, and the aliphatic polyamide is a resin (nylon 6) obtained from ε-caprolactam . The wiping cloth according to claim 2, wherein the weight ratio of the nylon MXD6 polymer to nylon 6 is 35:65 to 70:30 . The wiping cloth according to any one of claims 1 to 3, wherein in the split-type composite fiber, the polyamide resin composition and the polyester resin component after split splitting have a fineness of 0.5 dtex or less .

Images