JP4669942B2 - Polyamide monofilament for industrial fabric, process for producing the same, and industrial fabric - Google Patents

Description

  The present invention can effectively suppress the occurrence of misalignment when used in at least a part of an industrial fabric interwoven with a polyester monofilament, and has excellent wear resistance, high strength and durability. The present invention relates to a polyamide monofilament for industrial textiles capable of giving a high textile, a production method thereof, and an industrial textile using the polyamide monofilament for industrial textiles.

  Synthetic resin monofilaments are used for papermaking wires (papermaking nets), papermaking felts, papermaking fabrics such as paper dryer canvas, belt fabrics such as conveyor belts and dewatering belts, and filter fabrics such as various belt press filters. In addition, it has been widely used as a constituent material of various industrial fabrics.

  These industrial fabrics, when actually used, are worn out in contact with driving rolls and control rolls that are running, so that the synthetic resin monofilaments used in these fabrics have excellent resistance. Abrasion is required.

  In particular, in the papermaking industry, acid papermaking has been mainly produced in the past, but the problem of deterioration of paper over time has become prominent, and conversion to neutral papermaking has become active. .

  However, with the shift from acid paper to neutral paper making, calcium carbonate, which is harder than conventional talc, is used for fillers called fillers, and paper fabrics are increasingly worn during the paper making process. In particular, when a polyester monofilament is used as a constituent material of a papermaking fabric, there is a problem that the life of the fabric is shortened due to wear.

  In general, the abrasion resistance of the warp that composes the papermaking fabric has a great influence on the stability and life of the fabric, and when the warp is worn, the papermaking fabric changes in size and the warp is worn. When cut, the papermaking fabric itself is cut to shorten its life.

  Therefore, in order to improve the abrasion resistance of papermaking fabrics, polyamide monofilaments with higher abrasion resistance than polyester monofilaments are used in at least a part of upper and lower wefts, and polyester monofilaments and polyamide monofilaments are interwoven. Papermaking fabrics have already been put to practical use.

  However, since the conventional polyamide monofilament is easily affected by heat, the yarn quality is lowered, and the durability of the papermaking fabric is likely to be lowered.

  Therefore, polyamide monofilaments for industrial textiles, which are excellent in abrasion resistance and suitable for papermaking textiles, in which a hindered phenol compound and a bisamide compound are added to a nylon 6/66 copolymer (for example, see Patent Document 1). ) And polyamide monofilaments for industrial textiles in which an ionomer is blended with polyamide (for example, see Patent Document 2).

  However, in recent papermaking industries, it is difficult to maintain sufficient durability even with papermaking fabrics using these polyamide monofilaments for industrial fabrics as the papermaking speed increases and the amount of filler used increases. Accordingly, polyamide monofilaments for industrial textiles used for papermaking textiles have been required to have higher wear resistance.

  Moreover, high-viscosity polyester monofilaments have come to be used in recent papermaking fabrics to further improve durability, and in papermaking fabrics obtained by interweaving these high-viscosity polyester monofilaments and polyamide monofilaments, There is a need to heat set at high temperatures.

  As a result of the necessity of heat setting at a high temperature, not only has a new problem that misalignment tends to occur in industrial fabrics, in particular, papermaking fabrics, but polyamide monofilaments are polyester monofilaments. Due to the weak pressing force at the knuckle part, misalignment is likely to occur even in the fabric in use, which not only hinders the running stability of the fabric but also causes wrinkles caused by misalignment. This has led to the failure of the woven fabric and shortens the life of the paper woven fabric.

Under such circumstances, the development of polyamide monofilaments for industrial fabrics, which have higher wear resistance than conventional ones and hardly cause misalignment when interwoven with polyester monofilaments, is continually required. .
JP 2002-69748 A JP-A-2005-273112

  The purpose of the present invention is to effectively suppress the occurrence of misalignment when used in at least a part of an industrial fabric interwoven with a polyester monofilament, and has excellent wear resistance, high strength and durability. Another object of the present invention is to provide a polyamide monofilament for industrial textiles capable of providing a high-quality textile, a production method thereof, and an industrial textile using the polyamide monofilament for industrial textiles.

  In order to achieve the above object, according to the present invention, a polyamide monofilament used in at least a part of an industrial fabric interwoven with a polyester monofilament, wherein the polyhexahexene having a relative viscosity of sulfuric acid of 3.8 to 5.0 is used. It consists of methylene adipamide, the maximum value of the heat shrinkage stress when heated at 60 ° C./min is 0.25 to 0.45 cN / dtex, and the temperature when the heat shrinkage stress is maximum is 230 to 260 The number of flexural wear at the time of breaking in the flexural wear characteristic test measured in accordance with JIS L-1095-9.10.2B is 20,000 times or more, and in accordance with JIS L1013: 1999-8.18 Thus, there is provided a polyamide monofilament for industrial textiles, characterized in that the boiling water shrinkage measured in this way is 6.5 to 15%.

  In the polyamide monofilament for industrial textiles of the present invention, the tensile strength measured according to JIS L-1013: 1999-8.5 is 6.0 to 8.0 cN / dtex, and the tensile elongation is A more preferable condition is 20 to 50%.

  Further, the method for producing a polyamide monofilament for industrial textiles of the present invention comprises a polyhexamethylene adipamide having a relative viscosity of sulfuric acid of 3.8 to 5.0 when melt spinning and stretching, and a stretching temperature of 60 to 220 ° C., and The stretching ratio is set to 4.0 to 6.0 times, and subsequent to the stretching, a setting process is performed at a processing temperature of 5 to 45 ° C. and a setting ratio of 0.98 to 1.05 times.

  Furthermore, the industrial fabric of the present invention is characterized in that the polyamide monofilament for industrial fabric is used as at least a part of the constituent material and is interwoven with a polyester monofilament, especially when it is a papermaking fabric. It produces little effects such as low generation and excellent wear resistance.

  According to the polyamide monofilament for industrial textiles of the present invention, as described below, when used for at least part of the industrial textile interwoven with polyester monofilament, occurrence of misalignment can be effectively suppressed. An industrial fabric excellent in abrasion resistance, high strength and high durability, particularly a paper fabric can be obtained.

  Hereinafter, the present invention will be described in more detail.

  The polyamide monofilament for industrial textiles of the present invention is made of polyhexamethylene adipamide having a relative viscosity of sulfuric acid of 3.8 to 5.0, and the heat shrinkage stress of the polyamide monofilament when heated at 60 ° C./min. Bending measured at a maximum value of 0.25 to 0.45 cN / dtex, a temperature at which the heat shrinkage stress becomes maximum is 230 to 260 ° C., and according to the provisions of JIS L-1095-9.10.2B It is characterized in that the number of reciprocating wear at the time of fracture in the wear characteristic test is 20000 times or more, and the boiling water shrinkage measured according to JIS L1013: 1999-8.18 is 6.5 to 15%.

  Conventional polyamide resins include polycapramide (hereinafter referred to as nylon 6), polyhexamethylene sebacamide, polyhexamethylene dodecamide, poly (capramide / hexamethylene adipamide) copolymer, and poly (capramide / lauramide). ) Copolymers are known, but the polyamide monofilament for industrial textiles of the present invention has a polyhexamethylene azimuth because it has a high melting point among polyamide resins and is excellent in heat resistance and dimensional stability. Pamide (hereinafter referred to as nylon 66) is used.

  Further, the nylon 66 used for the polyamide monofilament for industrial textiles of the present invention needs to have a relative viscosity of sulfuric acid of 3.8 to 5.0, preferably 4.0 to 4.6, more preferably 4.0-4.2.

  When the relative viscosity of sulfuric acid is below the above range, not only is it difficult to obtain high-strength and high-abrasion polyamide monofilaments for industrial fabrics, but also yarn breakage or poor pushing of raw materials during melt spinning of polyamide monofilaments for industrial fabrics. When the obtained polyamide monofilament for industrial fabrics is used for papermaking fabrics, misalignment is likely to occur. On the other hand, when the relative viscosity of sulfuric acid exceeds the above range, the quality variation of the nylon 66 resin raw material becomes large, and when melt spinning using this raw material, troubles such as yarn breakage and poor indentation of the raw material are likely to occur.

  Here, the sulfuric acid relative viscosity is a value obtained by dissolving 2.5 g of a polyamide resin sample in 25 cc of 98% sulfuric acid according to JIS K6810 and using an Ostwald viscometer at a temperature of 25 ° C. It is.

  The polyamide monofilament for industrial textiles of the present invention can contain various additives according to the purpose, and examples of the additives include various antioxidants, light-resistant agents, flame retardants, and copper iodide. Anti-aging agents such as potassium iodide and 2-mercaptobenzimidazole, inorganic particles and pigments such as titanium oxide, silicon oxide, barium sulfate, clay, talc and carbon black, various pigments such as phthalocyanine metal and cobalt blue, And metal stearates such as calcium stearate, aluminum stearate, barium stearate, ε-caprolactam, ethylene bisstearylamide, stearic acid, calcium metasilicate, hydrous magnesium silicate, aminosilane, and melamine cyanurate it can.

  Next, the maximum value of the heat shrinkage stress of the polyamide monofilament for industrial textiles of the present invention needs to be 0.25 to 0.45 cN / dtex, preferably 0.30 to 0.40 cN / dtex.

  Further, the temperature at which the heat shrinkage stress becomes maximum needs to be 230 to 260 ° C, and preferably 240 to 255 ° C.

  If the maximum value of the heat shrinkage stress and the temperature at that time are below the above range, not only is it difficult to modify the surface of the woven industrial fabric, but also the pressing force at the knuckle part with the interwoven polyester monofilament. Is insufficient, and misalignment tends to occur.

  Here, the heat shrinkage stress means that the initial load of 10 g is applied to the polyimide monofilament, the shrinkage force (cN) of the polyimide monofilament generated when heated at 60 ° C. per minute is measured, and converted to unit fineness (dtex). It is what. The maximum value of the heat shrinkage stress and the temperature at that time are the heat shrinkage stress and the temperature at the peak read from the chart showing the relationship between the temperature and the heat shrinkage stress.

  In addition, the polyamide monofilament for industrial textiles of the present invention needs to have a bending wear number of 20,000 times or more at break in the bending wear characteristic test, and preferably 30000-70000 times.

  If the number of bending wears of the polyamide monofilament for industrial textiles is less than the above range, it is not preferable because it tends to be an industrial textile lacking abrasion resistance.

  Here, the number of times of bending wear is a value measured by a bending wear characteristic test according to JIS L-1095: 1999-9.10.2B method, and specifically, a fixed diameter of 1.0 mm. Two pieces of polyamide monofilament for industrial fabric brought into contact with a friction element (hard steel wire (SWP-A)) so that the polyamide monofilament for industrial textile bends at an angle of 55 ° to the left and right of the friction element. Under a free roller (100 mm distance between two rollers) and over another free roller, applying a load of 0.196 cN / dtex to one end of a polyamide monofilament for industrial textiles Set, the polyamide monofilament for industrial textiles is brought into reciprocating contact with the friction element at a speed of 120 reciprocations / minute and a reciprocating stroke of 25 mm. The number of times until the mid-monofilament breaks.

  Furthermore, the polyamide monofilament for industrial textiles of the present invention is required to have a boiling water shrinkage of 6.5 to 15% measured according to JIS L1013: 1999-8.18, preferably 8.15%. 5 to 12%.

  If the boiling water shrinkage rate of the polyamide monofilament for industrial textiles is below the above range, not only will the papermaking fabric after heat setting fall, but misalignment will easily occur, and conversely if it exceeds the above range, This is because a papermaking fabric lacking in dimensional stability is easily obtained.

  Furthermore, since the industrial fabric using the polyamide monofilament for industrial fabric of the present invention can be easily heat set at a temperature of 120 to 200 ° C., it is not necessary to heat set at a high temperature as in the case of a conventional industrial fabric. There is an advantage that misalignment due to heat setting can be inevitably eliminated.

  In addition, in the polyamide monofilament for industrial textiles of the present invention, in accordance with the provisions of JIS L-1013: 1999-8.5, because industrial textiles having higher durability such as strength and abrasion resistance can be obtained. It is preferable that the measured tensile strength is 6.0 to 8.0 cN / dtex, particularly 6.5 to 7.7 cN / dtex, and the tensile elongation is 20 to 50%, particularly 20 to 30%.

  The polyamide monofilament for industrial textiles of the present invention can be produced, for example, by the following method.

  First, nylon 66 resin is fed to an extruder type spinning machine having a metering gear pump and a spin block at the tip, and the nylon 66 resin is melt-kneaded at a temperature 20 to 60 ° C. higher than the melting point of the nylon 66 resin. Is spun from the spinneret and cooled and solidified to obtain an undrawn yarn.

  Next, the obtained undrawn yarn is drawn in two stages. In order to obtain desired heat shrinkage characteristics, wear resistance, and boiling water shrinkage characteristics, the first stage is drawn at a relatively low temperature and high magnification. The second-stage stretching is performed at a temperature higher than the first-stage stretching temperature so as to obtain stable stretchability so that the total stretching ratio is 4.0 to 6.0 times.

  This is because if the draw ratio is too low, it is difficult to obtain the desired heat shrinkage characteristics of the obtained polyamide monofilament for industrial fabrics. Conversely, if the draw ratio is too high, yarn breakage tends to occur. In order to obtain, it is preferable that it is 4.5 to 5.5 times.

  Also, if the stretching temperature is too low, a high tension is applied during stretching, which tends to cause thread breakage. Conversely, if it is too high, the melting point of the nylon 66 resin is close, and thread breakage tends to occur in the stretching bath. The temperature needs to be 60 to 220 ° C, and more preferably 70 to 200 ° C.

  Here, as the heat medium used in the stretching step, it can be easily removed from the surface of the polyamide monofilament for industrial textiles and essentially gives physical and chemical changes to the polyamide monofilament for industrial textiles. Any material can be used as long as it does not occur. However, since the present invention performs the first-stage stretching at a relatively low temperature, a warm water bath or a heated air bath is preferable from the economical viewpoint. In addition, as a heat medium used in the second stretching step, generally, a heating apparatus such as a liquid bath filled with an inert liquid having a high boiling point, an air furnace, an inert gas furnace, an infrared furnace, and a high-frequency furnace is used. Is preferred.

  The polyamide monofilament for industrial textiles stretched in two stages is subjected to a set treatment at room temperature in order to further improve and retain the desired heat shrinkage characteristics obtained in the stretching process. The treatment temperature is required to be 5 to 45 ° C, and more preferably 20 to 40 ° C.

  This set temperature condition is a condition necessary for obtaining desired heat shrinkage characteristics, wear resistance and boiling water shrinkage characteristics, and is different from conventional polyamide monofilaments for industrial textiles that are set under high temperature conditions. Manufacturing conditions.

  In addition, if the set magnification is too low, the boiling water shrinkage of the resulting polyamide monofilament for industrial textiles is low, so not only does the papermaking fabric after heat setting become poor, but misalignment is also likely to occur. Conversely, if the set magnification is too high, thread breakage is likely to occur. Therefore, the set magnification needs to be 0.98 to 1.05 times, and more preferably 0.99 to 1.01 times. preferable.

  Here, as the heating device used in the set processing step, a liquid bath filled with an inert liquid having a high boiling point similar to the above-described second-stage stretching, an air furnace, an inert gas furnace, an infrared furnace, a high-frequency furnace, etc. Can be mentioned.

  Then, the set monofilament for industrial textiles is applied with an oil agent on the surface as needed, and then wound around a winding tool.

  The polyamide monofilament for industrial textiles of the present invention thus obtained has heat shrinkage properties, abrasion resistance and boiling water shrinkage properties not found in conventional polyamide monofilaments. Therefore, this polyamide monofilament for industrial textiles is woven with polyester monofilament. When used for at least a part of the industrial fabric, the occurrence of misalignment can be effectively suppressed and the wear resistance is excellent compared to the case of using a conventional polyamide monofilament for industrial fabric. An industrial fabric with high strength and high durability can be obtained.

  In addition, the industrial fabric obtained by interweaving polyamide monofilament and polyester monofilament for industrial fabric of the present invention is not only used for papermaking, but also for belt fabrics such as conveyor belts and dewatering belts, and filter fabrics such as belt press filters. These various industrial fabrics that can be used can easily perform thermal correction of the woven surface, and can maintain a stable woven surface that is less prone to misalignment, Furthermore, it exhibits the effects such as excellent wear resistance.

  The polyamide monofilament for industrial textiles of the present invention is a single continuous yarn, but if necessary, a plurality of yarns may be combined and twisted and heat set, or a single yarn may be twisted and heat set. Good.

  In addition, the cross-sectional shape of the polyamide monofilament for industrial textiles of the present invention can be appropriately selected according to its use, and is not particularly limited. For example, a circle, an ellipse, a triangle, T, Y, Multi-leaf shape such as H, +, 5 leaf, 6 leaf, 7 leaf, 8 leaf, square, rectangle, rhombus, saddle shape and horseshoe shape can be mentioned, and these shapes are partially modified It may be.

  Furthermore, the diameter of the polyamide monofilament for industrial textiles of the present invention can also be appropriately selected according to its use, and is not particularly limited. The one with 1.00 mm is mainly used.

  Hereinafter, the polyamide monofilament for industrial textiles of the present invention will be described in more detail with reference to examples.

  The relative viscosity of sulfuric acid, melting point, heat shrinkage stress, tensile strength and elongation, boiling water shrinkage ratio, number of bending wear, operability in the yarn making process, evaluation of misalignment of fabric and wear resistance in the examples are as follows. went.

[Sulfuric acid relative viscosity (ηr)]
According to JIS K6810, 2.5 g of a polyamide resin sample was dissolved in 2.5 cc of 98% sulfuric acid and measured using an Ostwald viscometer at a temperature of 25 ° C.

[Maximum heat shrinkage stress and its temperature]
Using a thermomechanical analyzer TMA-60 manufactured by Shimadzu Corporation, the thermal contraction stress (cN / dtex) of the polyimide monofilament generated when the initial load of 10 g was applied to the polyimide monofilament and heated at 60 ° C. per minute was measured. . And the thermal contraction stress and temperature at the time of a peak were read from the chart which shows the relation between temperature and thermal contraction stress. The heat shrinkage stress (cN / dtex) is obtained by converting the shrinkage force (cN) of the polyimide monofilament generated by heat per unit fineness (dtex).

[Tensile strength and tensile elongation]
According to JIS L-1013: 1999-8.5, the tensile strength (cN / dtex) and tensile elongation (%) at break were measured under the conditions of a test length of 250 mm and a tensile speed of 300 mm / min. The tensile strength is obtained by converting the measured tensile strength (N) per unit fineness (dtex) of the measurement sample.

[Fineness]
It was measured according to a) A method of 8.5.1 of JIS L1015: 1999.

[Boiling water shrinkage]
Measured according to JIS L1013: 1999-8.18 shrinkage ratio.

[Number of bending wear]
In accordance with JIS L-1095: 1999-9.10.2B method, polyamide monofilament is frictioned with a polyamide monofilament that is brought into contact with a fixed 1.0 mm diameter friction element (hard steel wire (SWP-A)). Hang under two free rollers (distance 100 mm between the two rollers) provided to bend at an angle of 55 ° to the left and right of the child, and over another one free roller, A load of 0.196 cN / dtex was applied to one end of the polyamide monofilament, and the polyamide monofilament was reciprocally contacted with the friction element at a speed of 120 reciprocations / minute and a reciprocating stroke of 25 mm. The number of times until this was measured, and the average value was defined as the number of flexing wears. In addition, it shows that it is excellent in abrasion resistance, so that the frequency | count of bending wear is large.

[Operability]
The situation at the time of continuous extrusion spinning was observed, and the following three stages were evaluated based on the yarn breakage and the stability of pushing the raw material into the spinning machine.
○: No problem at all, very good,
Δ: There was some yarn breakage but operation was possible.
X: The operability was difficult due to frequent occurrences of thread breakage and indentation failure of raw materials.

[Practical evaluation of textiles]
Polyethylene terephthalate (hereinafter referred to as PET) monofilament having a diameter of 0.150 mm is used for the warp, and 0.170 mm diameter PET monofilament is used for the upper weft and the polyamide monofilament for industrial textiles having a diameter of 0.130 mm obtained in each of Examples and Comparative Examples. Furthermore, a 0.200 mm diameter PET monofilament for the lower weft and an endless 2.5-fold weave using a 0.200 mm diameter polyamide monofilament for industrial textiles manufactured under the same conditions as those of the Examples and Comparative Examples. The woven fabric was woven, and the woven fabric was heat-set at 190 ° C. to produce a papermaking wire having a basis weight of 800 g / m ² .

First, regarding the misalignment evaluation of the papermaking wire, the appearance (streaks, stripes, steps) of the obtained papermaking wire 1m ² was visually inspected, and the degree of misalignment was evaluated in the following five stages. In addition, 4 or more shall be a level with good appearance quality.
5: Streaks, stripes, steps are unknown
4: Depending on the angle, streaks, stripes, and steps are observed.
3: Regardless of the angle, slight streaks, stripes, and steps are recognized.
2: Lines, stripes and steps can be distinguished at a glance.
1: Generation of streaks, stripes and steps is remarkable.

  Furthermore, the obtained paper making wire was cut 10 mm in the weft direction and 100 mm in the warp direction to prepare a sample piece for wear resistance evaluation having a width of 10 mm and a length of 100 mm.

  Here, the surface of the sample piece that comes into contact with the drive roll of the papermaking wire is referred to as surface A, and the surface that contacts the papermaking wire is referred to as surface B.

  Then, one end of the sample piece is fixed so that the A surface of the sample piece is in contact with the 150 mm diameter ceramic cylindrical surface, and a load of 0.22 cN / dtex is applied to the other end of the sample piece. The piece was set on an abrasion resistance evaluation device.

  Thereafter, a filler for neutral papermaking (liquid temperature 30 ± 5 ° C.) containing 0.5% of calcium carbonate powder (Escalon (registered trademark), # 8000, manufactured by Sankyo Pharmaceutical Co., Ltd.) is applied to the B surface of the sample piece. The ceramic cylinder was rotated at 1500 rpm while dropping at 0.6 liter / min, and the time until the sample piece was cut was measured. It shows that it is a textile fabric excellent in abrasion resistance, so that the cutting time of a sample piece is long.

[Example 1]
Nylon 66 (manufactured by BASF Corporation, “Ultramid” A4, sulfuric acid relative viscosity ηr = 4.06) was used as the polyamide resin.

  This nylon 66 chip was supplied to a single-screw extruder type spinning machine, melted and kneaded, then melt-extruded from a nozzle hole via a gear pump for measurement, and led to a cooling water tank to be cooled and solidified.

  Next, the unstretched yarn that has been cooled and solidified is stretched in the first stage in a hot water bath at 80 ° C., and then in the hot air bath at 180 ° C., and the total stretch ratio is 4.80 times. Stretching was performed.

  Further, the polyamide monofilament for industrial textiles having a diameter of about 0.130 mm was obtained by performing a set treatment of 0.99 times in a room temperature air bath at 30 ° C.

[Examples 2 to 4]
A polyamide monofilament for industrial textiles was obtained using nylon 66 having the same relative viscosity of sulfuric acid as in Example 1 except that the stretching conditions and the setting conditions were changed as shown in Table 1.

[Examples 5 to 7]
The polyamide resin was changed to nylon 66 (BASF Corporation, “Ultramid” A5, sulfuric acid relative viscosity ηr = 4.69) having a relative sulfuric acid viscosity different from that of nylon 66 used in Examples 1 to 4. Except that, polyamide monofilaments for industrial textiles were obtained under the same conditions as in Examples 1 to 3.

[Comparative Example 1]
The polyamide resin was changed to nylon 66 (manufactured by Toray Industries, Inc., “Amilan” polyamide chip M3001, sulfuric acid relative viscosity ηr = 2.91) different from the nylon 66 used in Examples 1-7. Except this, a polyamide monofilament for industrial textiles was obtained under the same conditions as in Example 1.

[Comparative Examples 2 to 6]
A polyamide monofilament for industrial textiles was obtained using nylon 66 having the same relative viscosity of sulfuric acid as in Example 1 except that the stretching conditions and the setting conditions were changed as shown in Table 1.

[Comparative Example 7]
A polyamide monofilament for industrial textiles was prepared under the same conditions as in Example 1 except that the polyamide resin was changed to nylon 6 (manufactured by Toray Industries, Inc., “Amilan” polyamide chip M1041T, sulfuric acid relative viscosity ηr = 4.40). Obtained.

  The evaluation results of the polyamide monofilament for industrial textiles obtained in the examples and comparative examples are shown in Table 1.

  As is clear from the results in Table 1, the polyamide monofilaments for industrial textiles of the present invention (Examples 1 to 7) had a maximum value of heat shrinkage stress of 0.25 to 0.45 cN / dtex and a temperature at that time of 230 to The temperature was 260 ° C., the number of flexing wears was 20000 to 70000 times, and the boiling water shrinkage was 6.5 to 15%.

  Even under the same production conditions, polyamide monofilaments for industrial fabrics using nylon 66 having a relative viscosity of sulfuric acid ηr of 4.06 (Examples 1 to 3) are made of nylon 66 having a relative viscosity of sulfuric acid ηr of 4.69. It can be seen that this is a polyamide monofilament for industrial textiles that is superior in wear resistance and has a high boiling water shrinkage compared to the polyamide monofilament for industrial textiles used (Examples 5 to 7).

  On the other hand, the polyamide monofilament for industrial textiles (Comparative Examples 1 to 7) that does not satisfy the conditions of the present invention has at least one of heat shrinkage stress characteristics, wear resistance, and boiling water shrinkage of Examples 1 to 7. It was lower than the polyamide monofilament for industrial textiles.

  In addition, it can be seen from the results in Table 1 that the papermaking wires using the polyamide monofilaments for industrial textiles obtained in Examples 1 to 7 are less likely to cause misalignment and have excellent durability. .

  On the other hand, the papermaking wire using the polyamide monofilament for industrial textiles obtained in Comparative Examples 1-7 is not only easily misaligned but also lacks durability compared to the results of Examples 1-7. It was.

  As described above, the polyamide monofilament for industrial textiles of the present invention has heat shrinkage properties, abrasion resistance and boiling water shrinkage properties that are not found in conventional polyamide monofilaments. When used in at least a part of the weaving papermaking fabric, the occurrence of misalignment can be effectively suppressed and the wear resistance can be reduced as compared with the case of using a conventional polyamide monofilament for industrial fabrics. In addition, a high-strength and highly durable industrial fabric can be obtained.

  In addition, the industrial fabric obtained by interweaving the polyamide monofilament and the polyester monofilament for industrial fabric of the present invention is not only used for papermaking, but also for fabrics for belts such as conveyor belts and dewatering belts, and for filter fabrics such as filters for belt presses. These various industrial fabrics that can be used can easily perform thermal correction of the woven surface, and can maintain a stable woven surface that is less prone to misalignment, Furthermore, it exhibits the effects such as excellent wear resistance.

Claims (5)

Polyamide monofilament used for at least a part of industrial fabrics interwoven with polyester monofilament, which is made of polyhexamethylene adipamide having a relative viscosity of sulfuric acid of 3.8 to 5.0 and heated at 60 ° C. per minute. The maximum value of the heat shrinkage stress when heated is 0.25 to 0.45 cN / dtex, and the temperature when the heat shrinkage stress is maximized is 230 to 260 ° C., JIS L-1095-9.10.2B The number of flexural wear at the time of fracture in the flexural wear characteristic test measured according to the provisions of JIS L1013: The boiling water shrinkage measured according to the provisions of JIS L1013: 1999-8.18 is 6.5 to 15%. A polyamide monofilament for industrial textiles, characterized in that The tensile strength measured according to JIS L-1013: 1999-8.5 is 6.0 to 8.0 cN / dtex, and the tensile elongation is 20 to 50%. The polyamide monofilament for industrial textiles according to 1. When melt spinning and stretching polyhexamethylene adipamide having a relative viscosity of sulfuric acid of 3.8 to 5.0, the stretching temperature is set to 60 to 220 ° C. and the stretching ratio is set to 4.0 to 6.0 times. 3. The process for producing a polyamide monofilament for industrial textiles according to claim 1 or 2, wherein a setting treatment is performed at a treatment temperature of 5 to 45 [deg.] C. and a set magnification of 0.98 to 1.05 times. An industrial fabric obtained by using the polyamide monofilament for industrial fabric according to claim 1 or 2 as at least a part of a constituent material and interweaving with a polyester monofilament. The industrial fabric according to claim 4, which is a papermaking fabric.