JP2000144531A - Polyamide monofilament and industrial fabric - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyamide monofilament useful as a constituent yarn for an industrial fabric. SOLUTION: This polyamide monofilament comprises a copolyamide as a material which is obtained by polymerizing 10-90 mol% of a polyamide forming component composed of a salt of terephthalic acid or isophthalic acid and an aliphatic diamine with 90 mol% to 10 mol% of a polyamide forming component selected from a tri- or polycyclic lactam, an ω-amino acid and a salt of an aliphatic dicarboxylic acid and an aliphatic diamine and has the ratio n/m of number of amide groups (n) to methylene groups (m) in 1 constituent unit of <=0.19 and 800 poise to 5,000 poise melt viscosity measured at the melting point +15 deg.C at 10 second-1 shear rate. The monofilament is useful for an industrial fabric having a firm knuckle part and excellent abrasion resistance, such as a fabric for paper making apparatus and a filter cloth, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a small difference in properties between a dry state and a wet state without impairing the excellent characteristics such as abrasion resistance of a polyamide, and has excellent heat setting properties, and is particularly suitable for industrial fabric applications. The present invention relates to a novel polyamide monofilament and an industrial fabric using the polyamide monofilament, the knuckle portion of which is strong and can hold a stable woven surface.

[0002]

2. Description of the Related Art Conventionally, polyamide monofilaments have been widely used as industrial monofilaments, taking advantage of their excellent chemical and physical properties.

[0003] In an industrial fabric used for applications such as papermaking equipment, filter cloth, rubber reinforcement, and sieve mesh, a crossing portion between yarns (hereinafter abbreviated as a knuckle portion) is strong. Therefore, there is a demand for a property that does not generate misalignment or wrinkles, stabilizes the running of the fabric, and does not cause unevenness in the worn surface.

However, a fabric made of a monofilament made of a polyamide having a high amide group concentration such as polycaproamide (nylon 6) and polyhexamethylene adipamide (nylon 66) has a high water absorption of the material resin. When the fabric is used in a high humidity or water intervening environment, the rigidity and dimensional changes due to moisture absorption and desorption are large, which causes the knuckle part to loosen, causing misalignment and causing wrinkles. Not only hinders the running stability of the fabric, but also causes the wrinkles to be easily destroyed, resulting in a significant reduction in the life of the fabric.

On the other hand, monofilaments made of polyhexamethylene sebagamide (nylon 610), polyhexamethylene dodecamide (nylon 612), polyundecamide (nylon 11) or the like having a relatively low amide group concentration have a water absorbing property. The rate is low, and the property difference and dimensional change due to moisture absorption and desorption are small, so they are preferably used for brush applications, etc., but these monofilaments are inferior in heat setting properties and when used for industrial fabrics, Since the knuckle portion is not tight due to the setting of the greige machine for correcting the weave surface, the same problem as described above occurs.

[0006] Under these circumstances, various studies have been made to improve the properties of polyamide as a fiber material. For example, hexamethylene adipamide (66), hexamethylene terephthalamide (6T) and hexamethylene Highly heat-shrinkable polyamide fiber comprising isophthalamide (6I) (JP-A-52-85516) and a composition comprising a semi-aromatic polyamide resin comprising terephthalic acid, isophthalic acid and aliphatic diamine, and an aliphatic polyamide resin Polyamide filaments (Registered Patent No. 2712512) and the like are known, all of which are intended to increase the heat shrinkage of polyamide fibers, and when these are applied to monofilaments for industrial fabrics, , Due to too large heat shrinkage, Had included a bug that Nau.

[0007] As described above, polyamide monofilaments for industrial fabrics are required to have stability of physical properties, dimensional stability and heat setting property in a dry and wet environment.
It is not known that these properties are satisfied in a balanced manner.Conventional polyamide monofilaments lack any of the above-mentioned properties, and industrial fabrics composed of these polyamide monofilaments have a tightening force of a fabric knuckle portion. It is easy to cause misalignment due to lowering, leaving problems such as impairment of running stability of the fabric and generation of wrinkles.

[0008]

DISCLOSURE OF THE INVENTION The present invention has been achieved as a result of studying to solve the problems in the prior art described above, and has been made without impairing the excellent characteristics of polyamide such as abrasion resistance. Polyamide monofilament and knuckle part suitable for industrial fabric use have a small difference in characteristics between dry and wet conditions, and have excellent heat setting properties. It is an object of the present invention to provide an industrial fabric capable of retaining the same.

[0009]

According to the study of the present inventors, a copolyamide obtained by copolymerizing two specific polyamide-forming components and having a specific amide group concentration and melt viscosity is used as a material. Polyamide monofilaments used as
Alternatively, the present inventors have found that the above-mentioned object can be effectively achieved by the industrial fabric used for at least a part of the weft, and have reached the present invention.

That is, the polyamide monofilament of the present invention comprises 10 mol% to 90 mol% of a polyamide-forming component (A) comprising a salt of terephthalic acid and / or isophthalic acid and an aliphatic diamine; an amide in a unit of one unit obtained by polymerizing 90 mol% to 10 mol% of at least one polyamide-forming component (B) selected from salts of an ω-amino acid and an aliphatic dicarboxylic acid with an aliphatic diamine. The amide group concentration defined by the ratio n / m of the number of groups (n) and methylene groups (m) (however, the benzene ring of terephthalic acid and isophthalic acid is calculated assuming that the number of methylene groups (m) is 4) 0.19 or less, melting point + 15 ° C., shear rate 10 seconds ⁻¹ The melt viscosity measured under the conditions of 10 ⁻¹ is 800 poise to 15,000 poise. It is characterized by doing.

The polyamide / monofilament of the present invention has a wet / dry tensile strength ratio of 85% or more, a wet / dry flexural hardness ratio of 55% or more, and a maximum dimensional change in the longitudinal direction due to moisture absorption and desorption of 4%. Below, after heat-setting at a temperature of 100 ° C. to the melting point and in a tension state, it is cooled as it is, and the heat-setting tension ratio indicated by the ratio of the yarn tension at the time of reaching the normal temperature to the yarn tension before the heat treatment is twice or more. And the polyamide-forming component (A) is a salt of hexamethylenediamine and terephthalic acid, and the polyamide-forming component (B) is ω
-Laurolactam or 12-aminododecanoic acid is a preferable condition, and when these conditions are applied, it is expected that a more excellent effect is obtained.

The polyamide monofilament of the present invention which satisfies the above conditions has a small difference in properties between dry and wet conditions and excellent heat setting property without impairing the excellent characteristics of polyamide such as abrasion resistance. It is particularly suitable for use in industrial fabrics.

The industrial fabric of the present invention is characterized in that the above-mentioned polyamide monofilament is used for at least a part of a warp and / or a weft, and specific examples thereof include a fabric for a paper machine and a filter cloth.

According to the industrial fabric of the present invention, thermal correction of the woven surface of the fabric can be easily performed, the knuckle portion is strong, no misalignment occurs when the fabric is used, and a stable woven surface is maintained. Is possible.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

The copolymerized polyamide which is a constituent material of the polyamide monofilament of the present invention is a polymer obtained by copolymerizing the above-mentioned polyamide-forming components (A) and (B).

The polyamide-forming component (A) is a salt of terephthalic acid and / or isophthalic acid with an aliphatic diamine. Specific examples of the aliphatic diamine include ethylene diamine, tetramethylene diamine, hexamethylene diamine, and octadiamine. Methylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine and derivatives of these compounds in which part or all of the methylene group is substituted with a methyl group, an ethyl group or a halogen group, Can be used in combination of two or more.

On the other hand, the polyamide-forming component (B) is
Lactams having three or more rings are at least one selected from salts of ω-amino acids and aliphatic dicarboxylic acids and aliphatic diamines. Specific examples of lactams having three or more rings are ε-caprolactam, enantholactam , Capryllactam, ω-laurolactam and the like, specific examples of ω-amino acids include 6-aminocaproic acid, 7-aminoheptanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, α-pyrrolidone, α-piperidone Examples of the salt of an aliphatic dicarboxylic acid and an aliphatic diamine include aliphatic dicarboxylic acids such as adipic acid, sebacic acid, dodecandioic acid, and glutaric acid, and hexamethylene diamine, nonamethylene diamine, and decamethylene. Diamine, undecamethylenediamine, dodecamethylenediamine, meta-xylylenediamine Salts composed of an aliphatic diamine such may be mentioned, respectively.

Among them, the polyamide-forming component (A) is a salt of hexamethylenediamine and terephthalic acid, and the polyamide-forming component (B) is ω-laurolactam or
Copolyamide, which is 2-aminododecanoic acid, is preferably used.

The copolymerization ratio of the above components in the copolymerized polyamide is 10 mol% to 90 mol%, particularly 20 mol% to 60 mol%, and 90 mol% for the polyamide forming component (A). % To 10 mol%, especially 8%
It must be in the range of 0 mol% to 40 mol%. When the copolymerization ratio of the polyamide-forming component (A) is less than 10 mol%,
If the copolymerization ratio of the polyamide-forming component (B) exceeds 90 mol%, the heat set tension ratio of the obtained polyamide monofilament is undesirably reduced. Conversely, the copolymerization ratio of the polyamide-forming component (A) exceeds 90 mol%,
If the copolymerization ratio of the polyamide-forming component (B) is less than 10 mol%, excellent properties such as abrasion resistance unique to polyamide are impaired, which is not preferable.

The amide group concentration of the copolymerized polyamide determined by the type of the polyamide-forming component (A) and the polyamide-forming component (B) and the copolymerization ratio is limited to 0.19 or less. If the amide group concentration of the copolymerized polyamide exceeds 0.19, the property change due to moisture absorption and desorption in a polyamide monofilament becomes large, which is not preferable. With respect to the influence of moisture absorption and desorption, the lower the amide group concentration, the better, but the too low amide group is not preferred because the polyamide monofilament becomes rigid and tends to impair the abrasion resistance. Therefore, the preferred amide group concentration range is 0.10
０．１0.19, particularly 0.12 to 0.17.

Here, the amide group concentration in the copolymerized polyamide is defined by the ratio of the number of amide groups to the number of methylene groups in one unit of the resin composition, and is calculated by the following equation. Amide group concentration = n / m (where n is the number of amide groups (—NHCO—) in one unit of the copolymerized polyamide, and m is methylene group (—CH ₂ —) in one unit of the copolymerized polyamide. However, the benzene ring of terephthalic acid and isophthalic acid is calculated assuming that the number of methylene groups (m) is 4.)

Further, the above copolymerized polyamide has a melting point of +
The melt viscosity measured at a temperature of 15 ° C. and a shear rate of 10 seconds ⁻¹ is 800 poise to 15,000 poise, especially 2000
It is important to be in the range of poise to 10,000 poise.

The term "melt viscosity" as used herein means specifically a Shimadzu flow tester manufactured by Shimadzu Corporation or CFT-500.
It was measured at C.

If the melt viscosity of the copolymerized polyamide is lower than 800 poise, the strength of the obtained polyamide monofilament is lowered, and not only is it not practical for industrial fabrics, but also the spinnability is deteriorated during melt spinning. And the operability is inferior. Conversely, when the melt viscosity of the copolymerized polyamide is higher than 15,000 poise, it becomes difficult to discharge at the time of melt spinning, polymer decomposition is caused due to the need to increase the spinning temperature, and the spinning condition is deteriorated. Absent.

The melting point of the above copolymerized polyamide is 2
It is preferably in the range of 40 to 320 ° C., particularly 260 to 300 ° C., and the polyamide monofilament comprising the above-mentioned copolymerized polyamide of the present invention has a wet / dry tensile strength ratio of 85% or more and a wet / dry flexural hardness. It is important to satisfy the following characteristics: an aspect ratio of 55% or more, a dimensional change in moisture absorption and desorption of 4% or less, and a heat set tension ratio of 2 times or more.

Here, the wet / dry tensile strength ratio and the wet / dry flexural hardness ratio mean that a monofilament is immersed in water at 20 ° C.
It is the ratio between the value measured immediately after immersion for a period of time and the value measured immediately after standing for 24 hours in a test room in the standard state of JISL1013, and the tensile strength is measured according to JISL1013, section 7.5 and measured in cN / dtex. The value to be represented.
In addition, as shown in FIG. 1, the center of the sample wrapped around two pins (steel wires each having a diameter of 2 mm) placed at a distance of 1 cm is defined by a J-shaped hook (a steel wire having a diameter of 1 mm). This is a value represented by the maximum bending force (unit: mN) when the sample is bent by pulling up with the line).

In general, the industrial cloth is mounted on the apparatus with a relatively high tension in a relatively dry natural environment so as not to cause a problem such as wrinkles. Therefore, when the wet / dry tensile strength ratio of the polyamide monofilament constituting the fabric is less than 85%, the fabric tends to be broken when the fabric is used in a high humidity or water intervening environment, and the life tends to be short. Therefore, it is not preferable. Therefore, the wet / dry tensile strength ratio of the polyamide monofilament is 85%.
Preferably, it is at least 90%. In addition, the tensile strength of the monofilament made of the copolyamide of the present invention is 2.5 cN / dtex or more in a standard state of JISL1013.

The polyamide monofilament wet /
When the dry bending hardness ratio is lower than 55%, the tightening force of the knuckle portion is reduced when the fabric is used due to the difference in the dry and wet environment, and not only the misalignment tends to occur, but also the running of the fabric becomes unstable, and the This is not preferable because it causes the generation and the result that the service life of the fabric is significantly shortened. Therefore, the wet / dry bending hardness ratio of the polyamide monofilament is desirably 55% or more, more preferably 70% or more.

Further, the dimensional change in moisture absorption / desorption of the polyamide monofilament of the present invention is desirably 4% or less, particularly desirably 3% or less. Here, the dimensional change of moisture absorption / desorption refers to the dimension immediately after the spinning, and after immersion in water at 20 ° C. for 24 hours, in dry air at 20 ° C. (for example, in a desiccator filled with phosphorus pentoxide) for 24 hours or more. This is the amount of dimensional change at the time when the moisture content of the sample is reduced to 1% by weight or less.

A fabric woven with a polyamide monofilament having a dimensional change of more than 4% by moisture absorption / desorption is used when weaving the fabric in a relatively dry state and when the fabric is used in a high humidity or water intervening environment. The tightening force of the knuckle part is reduced due to the dimensional change due to the difference in the dry and wet environment from the time of attachment to the device, and the misalignment, unstable running of the fabric, generation of wrinkles, etc. are the same as when the wet / dry bending hardness ratio is low. Invites
It is not preferable because the service life of the fabric is significantly shortened.

The polyamide monofilament of the present invention preferably has a heat set tension ratio of at least 2 times, particularly at least 3 times. If the heat setting tension ratio is less than twice, the knuckle portion is loosened due to the correction of the weaving surface by the heat setting after weaving the fabric, and the same problem as described above is likely to occur when used as an industrial fabric.

The polyamide monofilament of the present invention comprises
It can be manufactured by a known method using a production facility similar to a normal polyamide monofilament.
For example, extruding a thread from a nozzle at a temperature selected from a range of 10 to 40 ° C. higher than the melting point of the copolymerized polyamide,
Liquid bath cooling or air cooling, once winding or subsequent direct stretching. The stretching temperature and the stretching ratio are generally in the range of 3 to 7 times from the glass transition temperature to the melting point of the copolymerized polyamide, but depending on the desired physical properties, multi-stage stretching of two or more stages at a temperature higher than the first-stage stretching, Further, it is heat-set at a fixed length or a relaxation.

The polyamide monofilament of the present invention comprises:
It is a continuous yarn composed of one single yarn and may have any cross-sectional shape such as a circle, a triangle, a square, or a polygon, or may be a composite monofilament with another polyamide and / or copolyamide. . The diameter of the cross section can be appropriately selected depending on the application, but is usually 0.05 mm to 3.0 m.
The range of m is most often used.

The polyamide monofilament of the present invention can contain other thermoplastic polymers in a small proportion, and further comprises a heat-resistant agent, a weather-resistant agent, a plasticizer, a matting agent,
Conventional additives such as abrasives, lubricants, antistatic agents, dyes and pigments can be included.

The polyamide monofilament of the present invention thus obtained has excellent novel properties of equilibrating physical properties, dimensional stability and heat setting property in a dry and wet environment, and is a constituent yarn of industrial fabric. Is extremely useful.

The industrial fabric of the present invention is obtained by weaving at least a part of the warp and / or weft constituting the fabric using the polyamide monofilament of the present invention. The weaving method of this industrial fabric can be appropriately selected depending on the application, and for example, a known weaving method such as plain weaving, twill weaving, double weaving, and triple weaving can be adopted.

Specific examples of the industrial cloth referred to in the present invention include papermaking nets, papermaking felt base fabrics, papermaking machine cloths such as papermaking canvas, filter cloths, sieves, conveyor belts, rubber reinforcing and screen gauze. However, especially when applied to papermaking equipment fabric and filter cloth,
Excellent effects can be obtained.

The industrial fabric of the present invention, particularly the fabric for a papermaking apparatus and the filter fabric, has a much stronger knuckle portion and misalignment as compared with those using conventional polyamide and / or copolymerized polyamide monofilaments. It is extremely useful because it has no wrinkles or the like, stabilizes the running of the fabric, and can efficiently use the excellent characteristics of the material such as abrasion resistance for a long time.

[0040]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist. The evaluation of the heat set tension ratio in the examples was performed using a thermal stress measurement device (type KE-2L) manufactured by Kanebo Engineering Co., Ltd.
After raising the temperature to an arbitrary temperature under the conditions of 44 cN / dtex and a heating rate of 100 ° C./min, the lid is opened and naturally cooled, the tension at normal temperature is read, and the heat set tension ratio (heat set tension ratio = heat set tension ratio = normal temperature Tension / initial tension).
Evaluation of other physical properties was performed according to the method described above.

Example 1 50 mol% of a polyamide molding component (A) composed of terephthalic acid and hexamethylenediamine and 50 mol% of a polyamide molding component (b) composed of ω-laurolactam were copolymerized. Melting point: 282
° C, melt viscosity: 1800 poise copolymerized polyamide,
It was supplied to an extruder having a diameter of 40 mm according to an ordinary method, extruded from a nozzle at a melt spinning temperature of 300 ° C, and cooled and solidified in a hot water bath at 90 ° C to obtain an undrawn yarn having a diameter of 467 µm. This unstretched yarn is stretched in the first stage three times in hot water at 95 ° C., and then stretched 1.5 times in a hot air oven at 120 ° C. to give a diameter of 220 μm. Was produced. The amide group concentration, wet / dry tensile strength ratio, wet /
Table 1 shows the results of evaluating the dry bending hardness ratio, the dimensional change in moisture absorption and desorption, and the heat set tension ratio.

[Example 2] Following the second-stage stretching of Example 1, a 10% relaxation heat treatment was carried out in a hot air oven at 230 ° C to produce a polyamide monofilament having a diameter of 220 µm. The results of evaluating the amide group concentration, the wet / dry tensile strength ratio, the wet / dry flexural hardness ratio, the dimensional change in moisture absorption / desorption and the heat set tension ratio of the obtained polyamide monofilament are also shown in Table 1.

Comparative Example 1 The polyamide molding component (A) and the polyamide molding component (B) in Example 1 had a molar ratio of 5 mol% and 95 mol%, respectively. Melting point: 265 ° C. Melt viscosity: 3000 poise A polyamide monofilament having a diameter of 220 μm was produced under the same conditions as in Example 1 except that the copolymerized polyamide was used and the melt spinning temperature was 290 ° C. The amide group concentration, wet / dry tensile strength ratio, wet / dry flexural hardness ratio, dimensional change in moisture absorption / desorption and heat set tension ratio of the obtained polyamide monofilament are also shown in Table 1.

Comparative Example 2 95 mol% of a polyamide molding component (A) composed of terephthalic acid and dodecamethylene diamine and 5 mol% of a polyamide molding component (B) composed of ω-laurolactam, Melting point: 250 ° C.
Melt viscosity: 1800 poise copolymer polyamide was added to 40
mm extruder and set the melt spinning temperature to 29
Except that the temperature was set to 0 ° C., the diameter was 220 under the same conditions as in Example 1.
A μm polyamide monofilament was produced. The amide group concentration, wet / dry tensile strength ratio, wet / dry flexural hardness ratio, dimensional change in moisture absorption / desorption and heat set tension ratio of the obtained polyamide monofilament are also shown in Table 1.

[Comparative Example 3] 55 mol of a polyamide molding component (A) composed of terephthalic acid and hexamethylenediamine and 45 mol of a polyamide molding component (B) composed of adipic acid and hexamethylenediamine were copolymerized. ,
A copolyamide having a melting point of 300 ° C. and a melt viscosity of 2,000 poise was spun and stretched under the same conditions as in Example 1 to produce a polyamide monofilament having a diameter of 220 μm. Amide group concentration, wet / dry tensile strength ratio, wet / dry flexural hardness ratio of the obtained polyamide monofilament,
Table 1 shows the evaluation results of the dimensional change of moisture absorption and desorption and the heat set tension ratio.
It is described together.

Table 1 Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Amide group concentration 0.14 0.14 0.09 0.12 0.20 Wet / dry tensile strength ratio 91% 95% 99 % 96% 79% Wet / dry bending hardness ratio 81% 79% 97% 85% 51% Change in moisture absorption / desorption 1.8% 1.3% 0.5% 1.5% 4.5% Heat set tension Comparative Example 4.0 times 6.1 times 0.9 times 11 times 3.5 times Comparative Example 4 A copolymer polyamide having the same composition as in Example 1 except that the melt viscosity was 700 poises was obtained. Spinning and stretching under the same conditions as 1 gives a diameter of 2
When a monofilament of 20 μm was produced, spun yarn frequently occurred, and not only could an undrawn yarn not be stably obtained, but the production was stopped due to the occurrence of many stretch breaks.

Comparative Example 5 The same copolymer polyamide as in Example 1 was used except that the melt viscosity was 18,000 poise.
A monofilament having a diameter of 220 μm was produced by spinning and stretching under the same conditions as in Example 1. However, since the yarn was bent at the hole of the die and discharge became difficult, the spinning temperature was increased to 310 ° C. The deteriorated polymer adhered around the hole of the die, and spinning could not be performed for a long time. Further, so-called fusi yarns, in which undrawn portions are mixed in the drawn yarns, frequently occurred, and normal products could not be obtained.

Example 3 A twill paper net was prepared by using the polyamide monofilament obtained in Example 1 for warp and weft. When this papermaking net was mounted on a neutral papermaking machine and put to practical use, it could be used without trouble up to a net thickness reduction rate of 40% due to abrasion, which is regarded as the net use limit. The usage period at this time was three months.

Comparative Example 6 A twill paper net was prepared by using the polyamide monofilament obtained in Comparative Example 1 for warp and weft. When this papermaking net was attached to a neutral papermaking machine and put to practical use, it was difficult to operate stably due to misalignment, and was removed from the papermaking machine for two months.

Comparative Example 7 A twill woven paper net was prepared by using the polyamide monofilament obtained in Comparative Example 2 for warp and weft. When the net was put on a neutral paper machine and put to practical use, the net thickness reduction rate reached 40% in 1.8 months, and the net was removed from the machine.

Comparative Example 8 A twill woven paper net was prepared by using the polyamide monofilament obtained in Comparative Example 3 for warp and weft. This papermaking net was mounted on a neutral papermaking machine and put into practical use. The net was broken in 1.5 months, and was removed from the papermaking machine.

[0052]

As described above, the polyamide monofilament of the present invention has excellent novel properties of equilibrating physical properties, dimensional stability and heat setting property in a dry and wet environment, and is suitable for industrial use. It is extremely useful as a constituent yarn of fabrics for use.

Further, the industrial fabric of the present invention, particularly the fabric for a papermaking apparatus and the filter fabric, has a strong knuckle portion, does not cause misalignment and wrinkles, stabilizes the running of the fabric, and has the durability of the material. An excellent effect that excellent characteristics such as abrasion can be efficiently used for a long time is exhibited.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a method for measuring the bending hardness of a polyamide monofilament of the present invention.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4L035 BB32 BB57 BB85 BB89 BB91 DD14 EE08 EE20 FF01 HH10 4L048 AA24 AA48 AA51 AA54 AB10 BA01 BA02 CA07 CA09 DA39 4L055 CE27 EA07 EA25 EA29 FA13 FA18 FA30

Claims (6)

[Claims] 1. A polyamide-forming component (A) comprising a salt of a terephthalic acid and / or isophthalic acid and an aliphatic diamine in an amount of 10 to 90 mol%, a lactam having three or more ring members, an ω-amino acid and an aliphatic dicarboxylic acid. An amide group (n) and a methylene group are obtained by polymerizing at least one kind of polyamide-forming component (B) 90 mol% to 10 mol% selected from salts of acids and aliphatic diamines. The amide group concentration defined by the ratio n / m of the number of (m) (provided that the number of methylene groups (m) in the benzene ring of terephthalic acid and isophthalic acid is 4) is 0.19 or less, and the melting point is +15. ℃ temperature, polyamide monofilament melt viscosity measured under the conditions of shear rate of 10 sec ^-1, characterized in that the material of the copolymerized polyamide is 800 poise ～15000 poise 2. The composition has a wet / dry tensile strength ratio of 85% or more, a wet / dry flexural hardness ratio of 55% or more, a maximum dimensional change in the longitudinal direction due to moisture absorption and desorption of 4% or less, and a temperature of 100 ° C. to the melting point. After heat setting at a temperature and a tension state, cooling is performed as it is, and a heat setting tension ratio indicated by a ratio of a yarn tension at a normal temperature to a yarn tension before a heat treatment is twice or more. Item 1
Polyamide monofilament according to 1. 3. The polyamide-forming component (A) is a salt of hexamethylenediamine and terephthalic acid, and the polyamide-forming component (B) is ω-laurolactam or
2. The composition of claim 1, which is 2-aminododecanoic acid.
Or the polyamide monofilament according to 2. 4. An industrial fabric, wherein the polyamide monofilament according to any one of claims 1 to 3 is used for at least a part of a warp and / or a weft. 5. The industrial fabric according to claim 4, wherein the industrial fabric is a paper machine fabric. 6. The industrial cloth according to claim 4, wherein said industrial cloth is a filter cloth.