CN106555249B

CN106555249B - Polyamide monofilament and preparation method and application thereof

Info

Publication number: CN106555249B
Application number: CN201510642948.1A
Authority: CN
Inventors: 郑毅; 秦兵兵; 冯淑芹; 刘修才
Original assignee: Cathay R&D Center Co Ltd; Cathay Industrial Biotech Ltd
Current assignee: Cathay Wusu Biomaterial Co ltd; Cathay R&D Center Co Ltd; CIBT America Inc
Priority date: 2015-09-30
Filing date: 2015-09-30
Publication date: 2020-06-05
Anticipated expiration: 2035-09-30
Also published as: CN106555249A

Abstract

The invention provides a polyamide monofilament and a preparation method and application thereof, wherein the production raw material of the polyamide monofilament at least contains polyamide resin, and the polyamide resin is prepared from at least 1, 5-pentanediamine and aliphatic long carbon chain dibasic acid as the production raw material; the production method of the polyamide monofilament comprises the following steps: carrying out spinning, cooling and forming, drafting and winding and shaping on the dried polyamide resin to obtain polyamide monofilaments; the production raw material of the polyamide monofilament contains odd-numbered carbon atom monomers, so that the proportion of hydrogen bonds formed among molecules of an amide group and the spatial arrangement of a crystal form and a molecular chain are different from those of the traditional polyamide monofilament taking even-numbered carbon atom monomers as the production raw material.

Description

Polyamide monofilament and preparation method and application thereof

Technical Field

The invention belongs to the technical field of polyamide materials, and relates to a polyamide monofilament as well as a preparation method and application thereof.

Background

Monofilament fibers made of polyamide materials are useful for making bristles for brushes because of their good abrasion resistance and good resiliency. For example, brush filaments made of nylon 6, nylon 610 or nylon 612 are common in the market.

In the case of the brush filaments made of nylon 6, although they have good abrasion resistance and rebound resilience, they have high water absorption and are liable to undergo permanent deformation in a humid environment, and thus are not excellent in durability.

Although the water absorption of the brush filaments made of nylon 610 and nylon 612 is reduced relative to the brush filaments made of nylon 6, both basically use petroleum derivatives, such as caprolactam and adipic acid or hexamethylenediamine, as production raw materials. The production process of the brush wire is complex as a whole, and not only has certain pollution, but also depends on non-renewable resources such as petroleum and the like.

Disclosure of Invention

A first object of the present invention is to provide a non-petroleum based polyamide monofilament having good abrasion resistance, high resilience, low water absorption and long service life at the same time.

The second purpose of the invention is to provide a preparation method of the polyamide monofilament, wherein the production raw material of the method is a non-petroleum-based material, which does not produce great pollution and is beneficial to environmental protection.

The third purpose of the invention is to provide the application of the polyamide monofilament.

A fourth object of the present invention is to provide a brush tool using the polyamide monofilament.

In order to achieve the above purpose, the solution of the invention is as follows:

a polyamide monofilament produced from a raw material containing at least a polyamide resin, the raw material containing at least 1, 5-pentanediamine.

In a preferred embodiment of the invention, the raw materials for the production of the polyamide filaments also contain other constituent polymers and/or auxiliaries.

In a preferred embodiment of the present invention, the raw material for producing the polyamide resin further contains an aliphatic long carbon chain dibasic acid, the number of carbon atoms of which is preferably 10 to 18. for example, the aliphatic long carbon chain dibasic acid may be any one or a combination of sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, octadecanedioic acid and △ 9-1, 18-octadecenedioic acid.

In a preferred embodiment of the present invention, both 1, 5-pentanediamine and the aliphatic long carbon chain dibasic acid can be prepared by biofermentation, and both can contain renewable organic carbon in accordance with ASTM D6866.

In a preferred embodiment of the present invention, the polyamide resin may contain additives in addition to the polyamide made of 1, 5-pentanediamine and an aliphatic long carbon chain dibasic acid. Additives include, but are not limited to, antioxidants, heat stabilizers, weathering agents, pigments, gloss enhancers, dyes, crystal nucleating agents, matting agents, plasticizers, antistatic agents, flame retardants, metals, metal salts, and the like. The above additives may be added in the alternative or in any combination.

When the polyamide resin contains polyamide and additives, the addition amount of the polyamide should not be less than 50% of the total weight of the polyamide resin and the addition amount of the additives should not be more than 50% of the total weight of the polyamide resin; however, it may also be preferable that the addition amount of the polyamide is not less than 70% by weight of the total weight of the polyamide resin and the addition amount of the additive is not more than 30% by weight of the total weight of the polyamide resin.

In a preferred embodiment of the present invention, the polyamide may preferably be any one or more of polyamide 510, polyamide 511, polyamide 512, polyamide 513, polyamide 514, polyamide 516 and polyamide 518.

In a preferred embodiment of the present invention, the viscosity number of the polyamide resin may be 100 to 400mL/g, further 120 to 240mL/g, further 130 to 200mL/g, further 135 to 180 mL/g.

In a preferred embodiment of the present invention, the content of the terminal amino group in the polyamide resin may be 5 to 100mol/ton, 10 to 70mol/ton, or 20 to 60 mol/ton.

In a preferred embodiment of the present invention, the initial modulus of the polyamide monofilament may be 1400 to 4200MPa, may be further 2000 to 3800MPa, and may be further 2600 to 3500 MPa.

In a preferred embodiment of the invention, the flexural resilience of the polyamide monofilament may be equal to or greater than 50%, may be further equal to or greater than 60%, and may be further equal to or greater than 65%.

In a preferred embodiment of the present invention, the polyamide monofilaments may have a diameter of 0.1 to 3.0 mm.

In a preferred embodiment of the invention, the breaking strength of the polyamide filaments may be 4.5N or more, and may further be 8N or more.

In a preferred embodiment of the present invention, the elongation at break of the polyamide monofilament may be 10 to 63%, and may be further 18 to 55%.

A preparation method of polyamide monofilament comprises the following steps: and (3) carrying out spinning, cooling and forming, drafting and winding and shaping on the dried polyamide resin to obtain the polyamide monofilament. Among them, the polyamide resin is the above-mentioned polyamide resin.

In a preferred embodiment of the present invention, the polyamide contained in the polyamide resin is prepared by a method comprising the steps of:

heating the polyamide salt aqueous solution in a polymerization kettle under the condition that the pH value is 7.5-8.9, exhausting when the pressure in the polymerization kettle reaches 0.2-2.0 Mpa, vacuumizing to 0-0.1 Mpa when the temperature reaches 220-290 ℃, and maintaining the vacuum degree for 0-60 min to obtain the polyamide.

In a preferred embodiment of the present invention, the spinning process comprises the steps of: the dried polyamide resin is sent into a spinning assembly after being sliced, heated, melted and extruded, and is subjected to high-pressure spinning to form fiber yarns.

In a preferred embodiment of the present invention, the drawing process comprises at least two drawing processes, and the ratio of the second drawing process to the first drawing process is 2-7.

The polyamide monofilament can be used in the production of brush filaments for use in brushing implements. For example, the brushing implement may be a toothbrush or a scrub brush; in this case, the diameter of each of the brush filaments may preferably be 0.15 to 0.35 mm.

A brushing tool, the brush filaments on the brush head of the brushing tool can be made of the polyamide monofilament. The brushing tool can be a toothbrush or a brushing brush; in this case, the diameter of each of the brush filaments may preferably be 0.15 to 0.35 mm.

Due to the adoption of the scheme, the invention has the beneficial effects that:

firstly, the raw material for producing the polyamide monofilament contains odd-numbered carbon atom monomers, the introduction of the odd-numbered carbon atom monomers effectively changes the proportion of hydrogen bonds among polyamide molecules, the spatial structure and the crystal form, and the polymerization, spinning process and monofilament performance of the polyamide monofilament are greatly different from those of the conventional polyamide monofilament (such as polyamide 66 or polyamide 612) which is prepared by taking even-numbered carbon atom monomers as the raw material.

Secondly, the raw materials for producing the polyamide monofilament at least comprise 1, 5-pentanediamine and aliphatic long carbon chain dibasic acid, both of which can be prepared by a biological fermentation method and can contain renewable organic carbon meeting the ASTM D6866 standard, so that the polyamide monofilament is a green material, does not depend on petroleum resources and does not cause serious pollution to the environment.

Thirdly, compared with the traditional polyamide monofilament prepared by taking an even number of carbon atom monomers as production raw materials, the polyamide monofilament provided by the invention has lower initial modulus (better softness) and higher elastic rebound rate (better lodging resistance); in addition, the initial modulus and the elastic resilience can be further adjusted by selecting the viscosity number and the drawing ratio of the polyamide resin, so that the application range of the polyamide resin is widened.

Detailed Description

The invention relates to a polyamide resin and a preparation method thereof, a polyamide monofilament containing the polyamide resin, a preparation method and application of the polyamide monofilament, and a brushing tool using the polyamide monofilament.

< Polyamide resin >

The raw material for producing the polyamide resin of the present invention contains at least polyamide produced from a diamine, a dibasic acid, or the like. However, according to the specific situation, the raw material for producing the polyamide resin may further contain an additive, but it is necessary to ensure that the addition amount of the polyamide is not less than 50% by weight of the total weight of the polyamide resin and the addition amount of the additive is not more than 50% by weight of the total weight of the polyamide resin, and it is also preferable that the addition amount of the polyamide is not less than 70% by weight of the total weight of the polyamide resin and the addition amount of the additive is not more than.

[ diamine ]

In the present invention, the diamine is preferably 1, 5-pentanediamine.

Among them, 1, 5-pentanediamine can be prepared by a chemical method, but is preferably prepared by a biological method. The biological method comprises producing 1, 5-pentanediamine by biological conversion method (such as fermentation method and enzyme conversion method) with bio-based raw material; or 1, 5-pentanediamine is produced by adopting petroleum-based raw materials through a biotransformation method; or biological raw materials are adopted to produce the 1, 5-pentanediamine by a chemical method. Thus, pentanediamine contains a renewable source of organic carbon that meets the ASTM D6866 standard.

Specifically, lysine or lysine salt can be subjected to lysine decarboxylase (such as EC 4.1.1.18) to remove carboxyl groups at two ends to produce 1, 5-pentanediamine, such as L-lysine decarboxylase property and application research (Jiangli, Nanjing university, Master thesis) disclosing a specific biological method for preparing pentanediamine; for example, the research on the transformation of L-lysine into cadaverine by microorganisms (ZhuJing, Tianjin science and technology university, Master's paper, 2009.3) also discloses a specific biological method for preparing pentanediamine.

[ dibasic acid ]

In the present invention, the dibasic acid is preferably an aliphatic long carbon chain dibasic acid, the number of carbon atoms of which may be preferably 10 to 18, and for example, the aliphatic long carbon chain dibasic acid may be preferably any one or a combination of sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, octadecanedioic acid and △ 9-1, 18-octadecenedioic acid, and may be more preferably sebacic acid or dodecanedioic acid.

In the present invention, the aliphatic long carbon chain dibasic acid may also be produced by a chemical method, but preferably is produced by a biological method, for example, the biological method may include producing the aliphatic long carbon chain dibasic acid by a biotransformation method (e.g., fermentation method, enzymatic conversion method) using a bio-based raw material; or the aliphatic long carbon chain dibasic acid is produced by adopting petroleum-based raw materials through a biotransformation method; or the aliphatic long carbon chain dibasic acid (such as sebacic acid and the like) is produced by a chemical method by adopting a bio-based raw material. Thus, the aliphatic long carbon chain dibasic acid may also contain a renewable source of organic carbon that meets ASTM D6866 standard.

[ additives ]

In the present invention, the raw materials for producing the polyamide resin may include various additives in addition to the above-described diamine and dibasic acid, according to the actual use requirements. These additives include, but are not limited to, antioxidants, heat stabilizers, weathering agents, pigments, gloss enhancers, dyes, crystal nucleating agents, matting agents, plasticizers, antistatic agents, flame retardants, metals, metal salts, and the like. The above additives may be added in the alternative or in any combination.

Among them, the heat stabilizer includes, but is not limited to, hindered phenol-based compounds, hydroquinone-based compounds, thiazole-based compounds, phosphorus-based compounds (e.g., phenylphosphonic acid), imidazole-based compounds (e.g., 2-mercaptobenzimidazole) and substitution products thereof, copper halide and iodine compounds, and the like.

Weathering agents include, but are not limited to, resorcinol, salicylates, benzotriazoles, benzophenones, hindered amines, and the like.

Pigments include, but are not limited to, cadmium sulfide, phthalocyanines, carbon black, and the like.

Gloss enhancers include, but are not limited to, titanium oxide and calcium carbonate, among others.

Dyes include, but are not limited to nigrosine and nigrosine, and the like.

Crystal nucleating agents include, but are not limited to talc, silica, kaolin, clay, and the like.

Plasticizers include, but are not limited to, octyl paraben, N-butylbenzenesulfonamide, and the like.

Antistatic agents include, but are not limited to, alkyl sulfate type anionic antioxidants, quaternary ammonium type cationic antistatic agents, nonionic antistatic agents (such as polyoxyethylene sorbitan monostearate), and betaine-based amphoteric antistatic agents, and the like.

Flame retardants include, but are not limited to, melamine cyanurate, hydroxides (such as magnesium hydroxide or aluminum hydroxide), ammonium polyphosphate, brominated polystyrene, brominated polyphenylene oxide, brominated polycarbonate, brominated epoxy resins, combinations of any bromine-based flame retardant with antimony trioxide, and the like.

[ Polyamide resin ]

In producing the polyamide resin of the present invention, it is ensured that at least one of 1, 5-pentanediamine and aliphatic long carbon chain dibasic acid is a bio-based product.

The polyamide resin of the present invention may be a polyamide resin containing polyamide 5X (X.gtoreq.10), and more preferably a polyamide resin containing any one or more of polyamide 510, polyamide 511, polyamide 512, polyamide 513, polyamide 514, polyamide 516, and polyamide 518. The following description will be given only by taking polyamide 510 and polyamide 512 as examples. The remaining types of polyamide are treated the same as polyamide 510 or polyamide 512.

For example, polyamide 510 is produced from at least 1, 5-pentanediamine and sebacic acid as production raw materials. When the polyamide resin further contains an additive, the amount P of the polyamide 510 to be added₁Not less than 50 percent (i.e. not more than 50 percent P) of the total weight of the polyamide resin₁100%) or less, in which case the additive is added in an amount A₁Should not exceed 50 percent of the total weight of the polyamide resin (i.e. 0 percent to A)₁< 50%); the amount of addition is preferably such that the amount P of addition of the polyamide 510 is₁Not less than 70 percent (i.e. more than 70 percent and less than or equal to P) of the total weight of the polyamide resin₁100%) or less, in which case the additive is added in an amount A₁Should not exceed 30 percent of the total weight of the polyamide resin (i.e. 0 percent to A)₁＜30％)。

For another example, polyamide 512 is produced from at least 1, 5-pentanediamine and dodecanedioic acid as production raw materials. When the polyamide resin further contains an additive, the amount P of the polyamide 512 added₂Not less than 50 percent (i.e. not more than 50 percent P) of the total weight of the polyamide resin₂100%) or less, in which case the additive is added in an amount A₂Should not exceed 50 percent of the total weight of the polyamide resin (i.e. 0 percent to A)₂< 50%); the amount of addition P of polyamide 512 is preferably such that₂Not less than 70 percent (i.e. more than 70 percent and less than or equal to P) of the total weight of the polyamide resin₂100%) or less, in which case the additive is added in an amount A₂Should not exceed 30 percent of the total weight of the polyamide resin (i.e. 0 percent to A)₂＜30％)。

For another example, when the polyamide resin contains the polyamide 510, the polyamide 512 and the additive together, the sum P of the addition amounts of the polyamide 510 and the polyamide 512₃Not less than 50 percent (i.e. not more than 50 percent P) of the total weight of the polyamide resin₃100%) or less, in which case the additive is added in an amount A₃Should not exceed 50 percent of the total weight of the polyamide resin (i.e. 0 percent to A)₃< 50%); the above addition amount may be preferably such that the sum P of the addition amounts of the polyamide 512 and the polyamide 512 is₃Not less than 70 percent (i.e. more than 70 percent and less than or equal to P) of the total weight of the polyamide resin₃100%) or less, in which case the additive is added in an amount A₃Should not exceed 30 percent of the total weight of the polyamide resin (i.e. 0 percent to A)₃＜30％)。

[ production method of Polyamide resin ]

The polyamide resin of the present invention (i.e., at least 1, 5-pentanediamine and an aliphatic long carbon chain dibasic acid as production raw materials) can be produced by a melt method or a solution thermal polycondensation method. Various process parameters can be adjusted according to performance requirements in the preparation process, such as: the concentration and pH of the aqueous polyamide salt solution, the polymerization temperature, the polymerization pressure, the degree of vacuum of polymerization, and the like.

In a preferred embodiment of the present invention, the method for producing the polyamide contained in the polyamide resin comprises the steps of:

(1) the preparation method comprises the following steps of replacing air with nitrogen in a 100-liter polymerization kettle (K/SY 166-2007 type), adding pure water with required quality into the reaction kettle, adding a certain amount of 1, 5-pentanediamine (which can contain renewable organic carbon meeting ASTM D6866 standard), stirring, adding an equimolar amount of aliphatic long carbon chain dibasic acid (the number of carbon atoms can be 10-18), adjusting the pH value to 7.5-8.9 by using a small amount of 1, 5-pentanediamine and the aliphatic long carbon chain dibasic acid (the pH value is detected by diluting the nylon saline solution to 10%), and preparing the nylon saline solution (namely the polyamide saline solution mentioned above).

(2) And heating in an oil bath in a nitrogen environment, starting to exhaust when the pressure in the polymerization kettle rises to 0.2-2.0 Mpa, vacuumizing to 0-minus 1Mpa when the temperature in the polymerization kettle reaches 220-290 ℃, and keeping the vacuum degree for 0-60 min to prepare the corresponding polyamide.

(3) And filling nitrogen into the polymerization kettle to the pressure of 0.4-0.5 Mpa, starting to melt and discharge, granulating by using a granulator to obtain polyamide chips, drying at 110 ℃, vacuum-drying for 24 hours, and then carrying out plastic packaging.

Wherein, in the step (1), after the pH value is adjusted, 200ppm of sodium hypophosphite corresponding to 100ppm of the total weight of the aliphatic long carbon chain dibasic acid and the 1, 5-pentanediamine can be added according to specific situations.

[ Properties of Polyamide resin ]

The properties of the polyamide resin of the present invention are as follows:

(1) viscosity number

In the present invention, the viscosity number of the polyamide resin is measured by the concentrated sulfuric acid method with an Ubbelohde viscometer, and the method comprises the following steps: a dried sample of a polyamide resin (e.g., polyamide 66, polyamide 510, polyamide 512, etc.) is accurately weighed at 0.25. + -. 0.0002g, dissolved by adding 50mL of concentrated sulfuric acid (96%), and the flow time t of the concentrated sulfuric acid is measured and recorded in a thermostatic water bath at 25 ℃₀And a flow time t of the polyamide resin sample solution.

The viscosity number calculation formula is as follows: viscosity number VN ═ t/t₀‐1)/C；

t-solution flow time;

t₀-the time of solvent flow;

c-concentration of polymer (g/mL).

Tests show that the polyamide resin can have the viscosity number of 100-400 mL/g in 96% sulfuric acid, can also have the viscosity number of 120-240 mL/g in 96% sulfuric acid, can preferably have the viscosity number of 130-200 mL/g in 96% sulfuric acid, and can more preferably have the viscosity number of 135-180 mL/g in 96% sulfuric acid.

In the process of preparing the polyamide monofilament, the viscosity number of the polyamide resin is controlled within a certain range, and if the viscosity number is too low, the filamentation of the polyamide resin is poor, so that the situation that the polyamide resin cannot be smoothly drawn into a fiber filament in a spinning procedure can occur; if the viscosity number is too high, the pressure of the spinning assembly is too high, and certain influence is also generated on smooth wire drawing. Meanwhile, the viscosity number has a certain influence on parameters such as mechanical strength, bending resilience, initial modulus, and the like of the polyamide monofilament, and therefore, the above-described preferable viscosity number is required for the polyamide resin.

(2) Terminal amino group content

In the present invention, the content of the terminal amino group of the polyamide resin is determined by the following method comprising the steps of: 1g of polyamide resin chips were dissolved at 30 ℃ under shaking in 50ml of a phenol/ethanol mixed solution (phenol/ethanol: 80/20) and the solution was titrated by neutralization with 0.02mol/L hydrochloric acid to determine the amount of 0.02mol/L hydrochloric acid used, H₁. The above phenol/ethanol mixed solvent was titrated with 0.02mol/L hydrochloric acid for a blank, and the amount H of 0.02mol/L hydrochloric acid was determined₂. From H₁And H₂The content of terminal amino groups per 1 ton of the polyamide resin sample was calculated from the difference therebetween.

As is apparent from the test, the content of the terminal amino group in the polyamide resin of the present invention may be 5 to 100mol/ton, or may be 10 to 70mol/ton, or may be preferably 20 to 60 mol/ton.

The content of the terminal amino groups in the polyamide resin is preferably selected because the content of the terminal amino groups is difficult to be reduced to less than 10mol/ton due to the limitation of an equilibrium constant during the polymerization process, and a certain content of the terminal amino groups is beneficial to improving the aging resistance of the polyamide resin and enabling the polyamide and additives to have better acting force so as to be beneficial to improving the overall performance of the polyamide resin.

< monofilament of Polyamide >

The raw material for producing the polyamide monofilament of the present invention contains at least the above-mentioned polyamide resin. However, the raw materials for the production of the polyamide filaments may also contain other constituent polymers and/or auxiliaries, as the case may be.

[ other constituent Polymer ]

In the present invention, the other constituent polymers are compounds other than polyamides prepared from 1, 5-pentanediamine and aliphatic long carbon chain dibasic acids.

(1) Other constituent polymers may contain structural units derived from: aliphatic carboxylic acids (e.g., oxalic acid, malonic acid, succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, etc.), alicyclic dicarboxylic acids (e.g., cyclohexanedicarboxylic acid, etc.), or aromatic dicarboxylic acids (e.g., terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, anthracenedicarboxylic acid, phenanthrenedicarboxylic acid, diphenyletherdicarboxylic acid, diphenoxyethanedicarboxylic acid, diphenylethanedicarboxylic acid, 1, 4-cyclohexanedicarboxylic acid, 5-sodiosulfoisophthalic acid, 5-tetrabutylphosphonium isophthalic acid, etc.), etc.

(2) Other constituent polymers may contain structural units derived from: aliphatic diamines (e.g., ethylenediamine, 1, 3-diaminopropane, 1, 4-diaminobutane, 1, 6-diaminohexane, 1, 7-diaminoheptane, 1, 8-diaminooctane, 1, 9-diaminononane, 1, 10-diaminodecane, 1, 11-diaminoundecane, 1, 12-diaminododecane, 1, 13-diaminotridecane, 1, 14-diaminotetradecane, 1, 15-diaminopentadecane, 1, 16-diaminohexadecane, 1, 17-diaminoheptadecane, 1, 18-diaminooctadecane, 1, 19-diaminononadecane, 1, 20-diaminoeicosane, 2-methyl-1, 5-pentanediamine, etc.), alicyclic diamines (e.g., cyclohexanediamine or bis- (4-aminohexyl) methane, etc.), or aromatic diamines (e.g., xylylenediamine, etc.), etc.

(3) Other constituent polymers may contain structural units derived from: aromatic, aliphatic or alicyclic diol compounds (e.g., ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol, 1, 4-cyclohexanedimethanol, neopentyl glycol, hydroquinone, resorcinol, dihydroxybiphenyl, naphthalene diol, anthracene diol, phenanthrene diol, 2-bis (4-hydroxyphenyl) propane, 4' -dihydroxydiphenyl ether, bisphenol S, or the like), and the like.

(4) Other constituent polymers may contain structural units derived from: aromatic compounds having a hydroxyl group and a carboxylic acid, aliphatic compounds, alicyclic hydroxycarboxylic acid compounds, and the like. Wherein the alicyclic hydroxycarboxylic acids include, but are not limited to, lactic acid, 3-hydroxypropionate, 3-hydroxybutyrate-valerate, hydroxybenzoic acid, hydroxynaphthalene carboxylic acid, hydroxyanthracene carboxylic acid, hydroxyphenanthrene carboxylic acid, and (hydroxyphenyl) vinyl carboxylic acid, and the like.

(5) Other constituent polymers may contain structural units derived from: amino acids (e.g., 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, p-aminomethylbenzoic acid, etc.) or lactams (e.g.,. epsilon. -caprolactam, or. epsilon. -laurolactam, etc.), etc.

(6) The other constituent polymer may be a comonomer copolymerizable with 1, 5-pentanediamine and the aliphatic long carbon chain dibasic acid, including, but not limited to, amino acids, lactams, aromatic dicarboxylic acids, aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, aromatic diols, aliphatic diols, alicyclic diols, aromatic diamines, aliphatic diamines, alicyclic diamines, aromatic hydroxycarboxylic acids, aliphatic hydroxycarboxylic acids, alicyclic hydroxycarboxylic acids, and derivatives of each of the foregoing comonomers. The derivatives of the above comonomers include reaction products of any two of the above comonomers, for example, a product obtained by reacting one amino group of one molecule of a diamine with one carboxyl group of one molecule of a dicarboxylic acid.

[ Properties of Polyamide monofilaments ]

The properties of the polyamide monofilaments of the invention are as follows:

(1) diameter of filament

The method for measuring the polyamide monofilament in the invention comprises the following steps: the average value is obtained after 10 points are detected by a vernier caliper.

The polyamide monofilament of the present invention may have a diameter of 0.1 to 3.0 mm. The diameter of the polyamide filaments is relevant to the field of application, the greater the diameter the greater its strength. When the polyamide monofilament is used as a toothbrush filament, the diameter of the polyamide monofilament can be 0.15-0.35 mm; when the polyamide monofilament is used as a fishing net wire, the diameter of the polyamide monofilament can be 0.1-1.0 mm; when the polyamide monofilament is used as a fishing line, the diameter thereof may be 0.15 to 3.0 mm.

(2) High breaking strength

The breaking strength of the polyamide monofilament of the present invention was measured by the method of GB/T21032-2007.

The breaking strength of the polyamide monofilament of the present invention is not less than 4.5N, preferably not less than 8N. The difference in the field of use determines the difference in the requirements for breaking strength of the polyamide filaments. The breaking strength of the polyamide monofilament can be adjusted by adjusting the technological parameters such as the viscosity number, the drawing ratio and the like of the polyamide resin. The greater the viscosity number and/or draw ratio, the greater the breaking strength.

(3) Elongation at break

The elongation at break of the polyamide monofilament of the present invention is measured by the method of GB/T21032-2007.

The elongation at break of the polyamide monofilament in the present invention may be 10 to 63%, and may preferably be 18 to 55%.

(4) Initial modulus

Initial modulus is a common indicator in monofilament testing, and represents softness of the filament. The initial modulus of the polyamide monofilament in the invention is measured according to the method of GB/T21032-2007 on a tensile curve, and the modulus of the polyamide monofilament at 1% elongation is taken as the initial modulus.

The initial modulus of the polyamide monofilament is preferably 1400-4200 MPa, more preferably 2000-3800 MPa, and further preferably 2600-3500 MPa.

During the course of the study, the inventors surprisingly found that: if a long carbon chain polyamide monofilament is prepared by using an odd-numbered carbon atom monomer (such as 1, 5-pentanediamine) as a production raw material, the initial modulus of the long carbon chain polyamide monofilament is obviously lower than that of a polyamide monofilament prepared by using a traditional even-numbered carbon atom monomer as a production raw material, which is probably because the introduction of the odd-numbered carbon atom monomer leads amide bonds not to completely form intermolecular hydrogen bonds, so that a flexible chain segment is lengthened. This finding offers the possibility to prepare ultra-soft polyamide monofilaments. If parameters such as viscosity number of the polyamide resin, drafting ratio of a drafting process and the like are adjusted in a matched mode, initial modulus of the polyamide monofilament can be further reduced or properly improved, so that the polyamide monofilament with different initial moduli can be prepared according to specific requirements, and application of the polyamide monofilament in different fields is possible. The lower the viscosity number and/or draw ratio, the lower the initial modulus in the range of application of the brush filaments.

(5) Bending resilience

The bending resilience is an important index in the fields of brush wires and the like, and the lodging resistance of the brush wires is reflected. Generally, the higher the flexural spring back, the longer the service life and the better the quality.

The flexural recovery of the polyamide monofilament of the present invention is measured by a method comprising the steps of: punching three through holes with the diameter of 1.5mm on a metal plate, respectively pushing the three polyamide monofilaments into the three holes from the middle of the polyamide monofilaments by using a soft blunt instrument, enabling the elbow parts to be flush with the other side of the metal plate, then putting the polyamide monofilaments into water at 50 ℃ for 2min, then putting the polyamide monofilaments into the water at 20 ℃ for 0.5min, taking out the polyamide monofilaments from the through holes, putting the polyamide monofilaments into the water at 20 ℃ for 15min for recovery, and measuring the included angle of the meter after taking out the polyamide monofilaments to obtain the bending resilience rate. Similarly, the bending resilience of any multifilament yarn composed of polyamide monofilaments (e.g., toothbrush yarn, shoe brush yarn or cleaning brush yarn, etc.) can be measured by the above-described method.

The bending resilience of the polyamide monofilament in the present invention may be preferably not less than 50%, more preferably not less than 60%, and still more preferably not less than 65%.

During the spinning process, the inventors surprisingly found that: under similar conditions, the flexural resilience of polyamide filaments produced using polyamide resins containing polyamide 5X (X.gtoreq.10) is higher than that of polyamide filaments produced using polyamide resins containing polyamide 6X (X.gtoreq.10), which cannot be explained by the conventional chain length theory. The inventor thinks that: the reason for this phenomenon is probably that half of amide bonds form intermolecular hydrogen bonds after odd-numbered carbon monomers (such as 1, 5-pentanediamine) are introduced as production raw materials, so that the soft points of the amide bonds are supported by alkane chain segments, and the bending rebound rate of the alkane chain segments is increased.

[ production method of Polyamide monofilaments ]

The preparation method of the polyamide monofilament comprises the following steps:

(1) drying the polyamide resin, and performing a spinning process to obtain fiber yarns;

(2) and sequentially carrying out cooling forming, drafting working procedures and winding and shaping on the fiber yarns to obtain the polyamide monofilament.

Wherein, in the step (1), the spinning process comprises the following steps: and (3) slicing the dried polyamide resin, continuously feeding the slices into a single-screw extruder, heating, melting and extruding the slices, feeding the slices into a spinning assembly, and carrying out high-pressure spinning to form the fiber yarns.

In the spinning process, the temperature of the single-screw extruder is controlled in a partitioning manner along the axial direction, the first zone heating temperature is 220-270 ℃, the second zone heating temperature is 225-310 ℃, the third zone heating temperature is 230-310 ℃, the fourth zone heating temperature is 240-300 ℃, the fifth zone heating temperature is 240-290 ℃, and the sixth zone heating temperature is 230-290 ℃. The selection of the temperature range of each region is comprehensively controlled according to the conditions of melting, mixing, fluidity and the like of the polyamide resin chips. If the temperature is too low, the plasticizing melting may be caused to be uneven, so that the spinnability may be deteriorated, and if the temperature is too high, side reactions such as decomposition may be generated, which also affect the spinnability of the polyamide resin and the properties of the polyamide monofilament.

The temperature of a spinning box of the spinning assembly is generally controlled to be 230-290 ℃, the temperature is adjusted according to the spinning condition and the pressure of a supply pump, if the temperature is too low, the pressure of the spinning assembly is increased, even equipment is damaged, a head-injected yarn is formed, and if the temperature is too high, the problems of degradation, no spinning and the like are easily caused.

The shape of the holes of the spinneret on the spinneret plate of the spinning pack is selected according to the cross-sectional shape of the polyamide filaments to be produced. The present invention prefers 44-hole spinnerets to uniformly discharge polyamide monofilaments having a circular cross-sectional shape. However, it can also be adjusted according to the actual situation.

In the step (2), in the cooling molding process, the spun fiber is cooled by a solidification method using cold water or a solidification method using cooling air, and preferably, a solidification method using cold water. In the invention, the spun fiber is cooled and formed in a water bath at 33 ℃.

In the step (2), the drawing process includes: and (3) taking the cooled and formed fiber filaments, performing primary drafting, then entering a near-boiling water bath (about 85 ℃) and performing secondary drafting, wherein the ratio of the two drafts is controlled to be 2-7. The two draft ratio is the ratio of the second draft to the first draft.

Through a large number of experiments, the inventor unexpectedly finds that the drawing ratio has a great influence on the initial modulus of the polyamide monofilament, the initial modulus is lower when the drawing ratio is lower, the initial modulus is improved to different degrees after the drawing ratio is improved, and the parameter is helpful for adjusting the initial modulus of the polyamide monofilament, so that the polyamide monofilament with different initial moduli, which can be used in different environments, can be obtained.

In the step (2), the winding and shaping include: and winding the filaments formed by the drawing process onto a square ring, transferring the filaments into a steam kettle at 110 ℃ after the filaments are fully wound, carrying out heat setting for 0.5 hour, and finally transferring the filaments into a drying room at 50 ℃ for drying to obtain the polyamide filaments (finished products). The heat-setting temperature and time can be adjusted as the case may be.

The present invention will be further described below with reference to preparation examples, examples and comparative examples.

Preparation example one (Polyamide 510)

The preparation example provides a preparation method of polyamide 510, which comprises the following steps:

(1) displacing air by using nitrogen in a 100-liter polymerization kettle (K/SY 166-2007 type), adding 30kg of pure water into the reaction kettle, then adding 10.06kg (98.5mol) of 1, 5-pentanediamine (containing organic carbon of renewable sources meeting the ASTM D6866 standard), stirring, adding 19.93kg (98.5mol) of sebacic acid, adjusting the pH value to 8.43 by using a small amount of 1, 5-pentanediamine and sebacic acid (taking a nylon saline solution to dilute to 10% to detect the pH value), and preparing a nylon saline solution;

(2) heating the mixture by adopting an oil bath under a nitrogen environment, gradually increasing the temperature of the oil bath to 280 ℃, starting to exhaust when the pressure in the polymerization kettle is increased to 1.73Mpa, vacuumizing to-0.06 Mpa when the temperature in the polymerization kettle reaches 265 ℃, and keeping the vacuum degree for 20min to obtain polyamide 510;

(3) and filling nitrogen into the polymerization kettle to the pressure of 0.4Mpa, starting to melt and discharge, granulating by using a granulator, drying at 110 ℃, vacuum-drying for 24 hours, and then carrying out plastic packaging.

Preparation example two (Polyamide 510)

(1) a 100-liter polymerization kettle (K/SY 166-2007 type) is used for replacing air with nitrogen, 12.8kg of pure water is added into the reaction kettle, 10.06kg (98.5mol) of 1, 5-pentanediamine (containing organic carbon of renewable sources meeting the ASTM D6866 standard) is added into the reaction kettle, 19.93kg (98.5mol) of sebacic acid is added after stirring, the pH value is adjusted to 8.20 by a small amount of 1, 5-pentanediamine and sebacic acid (the pH value is detected by taking the nylon saline solution to be diluted to 10 percent), and the nylon saline solution is prepared;

(2) heating the mixture by adopting an oil bath under a nitrogen environment, gradually increasing the temperature of the oil bath to 280 ℃, starting to exhaust when the pressure in the polymerization kettle is increased to 1.0Mpa, vacuumizing to-0.055 Mpa when the temperature in the polymerization kettle reaches 265 ℃, and keeping the vacuum degree for 20min to obtain polyamide 510;

Preparation example III (Polyamide 510)

(1) a 100-liter polymerization kettle (K/SY 166-2007 type) is used for replacing air with nitrogen, 12.8kg of pure water is added into the reaction kettle, 10.06kg (98.5mol) of 1, 5-pentanediamine (containing organic carbon of renewable sources meeting the ASTM D6866 standard) is added into the reaction kettle, 19.93kg (98.5mol) of sebacic acid is added after stirring, the pH value is adjusted to 8.22 by a small amount of 1, 5-pentanediamine and sebacic acid (the pH value is detected by taking the nylon saline solution to be diluted to 10 percent), and the nylon saline solution is prepared;

(2) heating the mixture by adopting an oil bath under a nitrogen environment, gradually increasing the temperature of the oil bath to 280 ℃, starting to exhaust when the pressure in the polymerization kettle is increased to 1.0Mpa, vacuumizing to-0.065 Mpa when the temperature in the polymerization kettle reaches 265 ℃, and keeping the vacuum degree for 20min to obtain polyamide 510;

Preparation example four (Polyamide 510)

(1) displacing air by using nitrogen in a 100-liter polymerization kettle (K/SY 166-2007 type), adding 12.8kg of pure water into the reaction kettle, then adding 10.06kg (98.5mol) of 1, 5-pentanediamine (containing renewable organic carbon meeting ASTM D6866 standard), stirring, adding 19.93kg (98.5mol) of sebacic acid, adjusting the pH value to 8.5 by using a small amount of 1, 5-pentanediamine and sebacic acid (diluting a nylon saline solution to 10% for detecting the pH value), and then adding sodium hypophosphite which is equivalent to 200ppm of the total weight of dibasic acid (sebacic acid) and diamine (1, 5-pentanediamine) to prepare a nylon saline solution;

(2) heating by adopting an oil bath under a nitrogen environment, gradually increasing the temperature of the oil bath to 288 ℃, starting to exhaust when the pressure in the polymerization kettle is increased to 1.2Mpa, vacuumizing to-0.07 Mpa when the temperature in the polymerization kettle reaches 268 ℃, and keeping the vacuum degree for 25min to obtain polyamide 510;

(3) and filling nitrogen into the polymerization kettle to the pressure of 0.5Mpa, starting to melt and discharge, granulating by using a granulator, drying at 110 ℃ for 24 hours in vacuum, and then carrying out plastic packaging.

Preparation example five (Polyamide 511)

The preparation example provides a preparation method of polyamide 511, which comprises the following steps:

(1) displacing air by using nitrogen in a 100 liter polymerization kettle (K/SY 166-2007 type), adding 12.8kg of pure water into the reaction kettle, then adding 9.63kg (94.2mol) of 1, 5-pentanediamine (containing organic carbon of renewable sources meeting the ASTM D6866 standard), stirring, adding 20.37kg (94.2mol) of undecanedioic acid, adjusting the pH value to 8.31 by using a small amount of 1, 5-pentanediamine and the undecanedioic acid (taking a nylon saline solution to dilute to 10% to detect the pH value), and then adding 100ppm of sodium hypophosphite corresponding to the total weight of the dibasic acid (undecanedioic acid) and the diamine (1, 5-pentanediamine) to prepare a nylon saline solution;

(2) heating the mixture by adopting an oil bath under a nitrogen environment, gradually increasing the temperature of the oil bath to 280 ℃, starting to exhaust when the pressure in a polymerization kettle is increased to 1.73Mpa, vacuumizing to-0.05 Mpa when the temperature in the kettle reaches 265 ℃, and keeping the vacuum degree for 20min to obtain polyamide 511;

Preparation example six (Polyamide 512)

In this example, the procedure was the same as in preparation example V except that the dibasic acid in preparation example V was adjusted to dodecanedioic acid, the amount of the dibasic acid added was adjusted to 20.78kg (90.2mol), the amount of the 1, 5-pentanediamine added was adjusted to 9.22kg (90.2mol), the pH was adjusted to 8.46, and sodium hypophosphite was not added, and the concrete procedure was as follows:

the preparation example provides a preparation method of polyamide 512, which comprises the following steps:

(1) replacing air with nitrogen in a 100-liter polymerization kettle (K/SY 166-2007 type), adding 12.8kg of pure water into the reaction kettle, then adding 9.22kg (90.2mol) of 1, 5-pentanediamine (containing organic carbon which meets ASTM D6866 standard and is renewable in source), stirring, adding 20.78kg (90.2mol) of dodecanedioic acid, adjusting the pH value to 8.46 by using a small amount of 1, 5-pentanediamine and the dodecanedioic acid (taking a nylon saline solution to dilute to 10% to detect the pH value), and preparing the nylon saline solution without adding sodium hypophosphite;

(2) and heating the mixture by adopting an oil bath under a nitrogen environment, gradually increasing the temperature of the oil bath to 280 ℃, starting to exhaust when the pressure in the polymerization kettle is increased to 1.73Mpa, vacuumizing to-0.05 Mpa when the temperature in the polymerization kettle reaches 265 ℃, and keeping the vacuum degree for 20min to obtain the polyamide 512.

Preparation example seven (Polyamide 513)

In this example, the procedure was the same as in preparation example V except that the dibasic acid in preparation example V was adjusted to tridecanedioic acid, the amount of the dibasic acid added was adjusted to 21.15kg (86.6mol), the amount of the 1, 5-pentanediamine added was adjusted to 8.85kg (86.6mol), the pH was adjusted to 8.44, and the vacuum applied was-0.06 MPa, and the concrete procedure was as follows:

(1) displacing air by using nitrogen in a 100 liter polymerization kettle (K/SY 166-2007 type), adding 12.8kg of pure water into the reaction kettle, then adding 8.85kg (86.6mol) of 1, 5-pentanediamine (containing organic carbon of renewable source meeting ASTM D6866 standard), stirring, adding 21.15kg (86.6mol) of tridecanedioic acid, adjusting the pH value to 8.44 by using a small amount of 1, 5-pentanediamine and the tridecanedioic acid (taking the nylon saline solution to dilute to 10% to detect the pH value), and then adding 100ppm of sodium hypophosphite corresponding to the total weight of the dibasic acid (tridecanedioic acid) and the diamine (1, 5-pentanediamine) to prepare a nylon saline solution;

(2) heating the mixture by adopting an oil bath under a nitrogen environment, gradually increasing the temperature of the oil bath to 280 ℃, starting to exhaust when the pressure in the polymerization kettle is increased to 1.73Mpa, vacuumizing to-0.06 Mpa when the temperature in the polymerization kettle reaches 265 ℃, and keeping the vacuum degree for 20min to obtain polyamide 513;

Preparation example eight (Polyamide 514)

In this example, the procedure was followed as in preparation example VII except that the dibasic acid in preparation example V was adjusted to tetradecanedioic acid, the amount of 1.50kg (83.2mol) of 1, 5-pentanediamine was adjusted to 8.50kg (83.2mol), and the pH was adjusted to 8.58:

(1) displacing air by using nitrogen in a 100-liter polymerization kettle (K/SY 166-2007 type), adding 12.8kg of pure water into the reaction kettle, then adding 8.05kg (83.2mol) of 1, 5-pentanediamine (containing organic carbon which meets ASTM D6866 standard and is renewable in source), stirring, adding 21.15kg (83.2mol) of tetradecanedioic acid, adjusting the pH value to 8.58 by using a small amount of 1, 5-pentanediamine and tetradecanedioic acid (taking a nylon saline solution to dilute to 10% to detect the pH value), and then adding 100ppm of sodium hypophosphite corresponding to the total weight of the dibasic acid (tetradecanedioic acid) and the diamine (1, 5-pentanediamine) to prepare a nylon saline solution;

(2) heating the mixture by adopting an oil bath under a nitrogen environment, gradually increasing the temperature of the oil bath to 280 ℃, starting to exhaust when the pressure in the polymerization kettle is increased to 1.73Mpa, vacuumizing to-0.06 Mpa when the temperature in the polymerization kettle reaches 265 ℃, and keeping the vacuum degree for 20min to obtain polyamide 514;

Preparation example nine (Polyamide 516)

In this example, the procedure was followed except that the dibasic acid in preparation example VII was adjusted to hexadecanedioic acid, the amount of the dibasic acid added was adjusted to 22.11kg (77.2mol), the amount of the 1, 5-pentanediamine added was adjusted to 7.89kg (77.2mol), and the pH was adjusted to 8.62:

(1) displacing air by using nitrogen in a 100 liter polymerization kettle (K/SY 166-2007 type), adding 12.8kg of pure water into the reaction kettle, then adding 7.89kg (83.2mol) of 1, 5-pentanediamine (containing organic carbon of renewable sources meeting the ASTM D6866 standard), stirring, adding 22.11kg (77.2mol) of hexadecanedioic acid, adjusting the pH value to 8.62 by using a small amount of 1, 5-pentanediamine and the hexadecanedioic acid (taking the nylon saline solution to dilute to 10% to detect the pH value), and then adding 100ppm of sodium hypophosphite corresponding to the total weight of the dibasic acid (hexadecanedioic acid) and the diamine (1, 5-pentanediamine) to prepare a nylon saline solution;

(2) heating the mixture by adopting an oil bath under a nitrogen environment, gradually increasing the temperature of the oil bath to 280 ℃, starting to exhaust when the pressure in the polymerization kettle is increased to 1.73Mpa, vacuumizing to-0.06 Mpa when the temperature in the polymerization kettle reaches 265 ℃, and keeping the vacuum degree for 20min to prepare polyamide 516;

Preparation ten (Polyamide 518)

In this example, the procedure was followed except that the dibasic acid in preparation example VII was adjusted to octadecanedioic acid, the amount of 22.64kg (72.0mol) of the dibasic acid, the amount of 7.36kg (72.0mol) of 1, 5-pentanediamine and the pH of 8.59 were adjusted to obtain a solution, and the following steps were carried out:

(1) a100-liter polymerization kettle (K/SY 166-2007 type) is used for replacing air with nitrogen, 12.8kg of pure water is added into the reaction kettle, 7.36kg (72.0mol) of 1, 5-pentanediamine (containing organic carbon which meets the ASTM D6866 standard and is of renewable source) is added, after stirring, 22.64kg (72.0mol) of octadecanedioic acid is added, the pH value is adjusted to 8.59 by using a small amount of 1, 5-pentanediamine and octadecanedioic acid (the pH value is detected by diluting the nylon saline solution to 10 percent), and sodium hypophosphite which is 100ppm corresponding to the total weight of the dibasic acid (octadecanedioic acid) and the diamine (1, 5-pentanediamine) is added to prepare the nylon saline solution.

(2) And heating the mixture by adopting an oil bath under a nitrogen environment, gradually increasing the temperature of the oil bath to 280 ℃, starting to exhaust when the pressure in the polymerization kettle is increased to 1.73Mpa, vacuumizing to-0.06 Mpa when the temperature in the polymerization kettle reaches 265 ℃, and keeping the vacuum degree for 20min to obtain the polyamide 518.

Comparative preparation example 1 (Polyamide 66)

The present comparative preparation example provides a method for preparing polyamide 66, which comprises the following steps:

(1) a 100-liter polymerization kettle (K/SY 166-2007 type) is used for replacing air with nitrogen, 30kg of pure water is added into the reaction kettle, 13.28kg (114.3mol) of hexamethylene diamine (containing organic carbon which meets the ASTM D6866 standard and can be regenerated) is added, after stirring, 16.72kg (114.3mol) of hexanedioic acid is added, the pH value is adjusted to 7.83 by a small amount of hexamethylene diamine and adipic acid (the pH value is detected by taking a nylon salt aqueous solution to be diluted to 10 percent), and a nylon salt aqueous solution is prepared;

(2) heating by adopting an oil bath under a nitrogen environment, gradually increasing the temperature of the oil bath to 298 ℃, starting to exhaust when the pressure in the polymerization kettle is increased to 1.73Mpa, vacuumizing to-0.04 Mpa when the temperature in the polymerization kettle reaches 275 ℃, and keeping the vacuum degree for 20min to obtain polyamide 66;

Comparative preparation example two (Polyamide 612)

This comparative preparation example provides a method for preparing polyamide 612, which comprises the steps of:

(1) a100-liter polymerization reactor (type K/SY 166-2007) was purged with nitrogen, 45kg of pure water was added to the reaction tank, 10.06kg (86.5mol) of hexamethylenediamine (containing a renewable organic carbon satisfying ASTM D6866 standard) was then added, and after stirring, 19.93kg (86.5.5mol) of dodecanedioic acid was added, and the pH was adjusted to 7.99 with a small amount of hexamethylenediamine and dodecanedioic acid (the pH was measured by diluting the aqueous solution of nylon salt to 10%), to obtain an aqueous solution of nylon salt.

(2) And heating the mixture by adopting an oil bath under a nitrogen environment, gradually increasing the temperature of the oil bath to 280 ℃, starting to exhaust when the pressure in the polymerization kettle is increased to 1.73Mpa, vacuumizing to-0.05 Mpa when the temperature in the polymerization kettle reaches 265 ℃, and keeping the vacuum degree for 20min to obtain the polyamide 612.

The parameters of the production methods of the first to tenth production examples and the first and second comparative production examples are shown in the following tables 1 and 2. The viscosity numbers and the terminal amino group contents of the polyamide resins obtained in preparation examples one to ten are shown in Table 3.

Table 1 shows the addition amounts of the respective components in preparation examples one to ten and comparative preparation examples one and two

Table 2 is a table of process parameters of the production methods of production examples one to ten and comparative production examples one and two

Table 3 is a table of values of viscosity numbers and terminal amino group contents of the polyamide resins obtained in production examples one to ten and comparative production examples one and two

Species of	Preparation of the product	Viscosity number (mL/g)	Content of terminal amino groups (mol/ton)
				Preparation example 1	Polyamide 510	137.1	46.5
Preparation example two	Polyamide 510	149.3	49.6
				Preparation example three	Polyamide 510	167.2	42.8
Preparation example four	Polyamide 510	190.1	33.6
				Preparation example five	Polyamide 511	142.3	35.7
Preparation example six	Polyamide 512	135.2	45.1
				Preparation example seven	Polyamide 513	136.4	41
Preparation example eight	Polyamide 514	141.6	38.5
				Preparation example nine	Polyamide 516	138.7	42.6
Preparation example ten	Polyamide 518	136.7	41.8
				Comparative preparation example 1	Polyamide 66	142.1	42.1
Comparative preparation example 2	Polyamide 612	140.6	44.3

EXAMPLE one (Polyamide 510 monofilament)

This example provides a method for preparing polyamide 510 monofilament, which includes the following steps:

(1) taking 20kg of polyamide 510 slices in the preparation example I, drying, continuously feeding into a single-screw extruder, heating, extruding and melting to obtain a polyamide 510 melt, and controlling the single-screw extruder in a partition mode along the axial direction, wherein the heating temperature of a first zone is 270 ℃, the heating temperature of a second zone is 300 ℃, the heating temperature of a third zone is 300 ℃, the heating temperature of a fourth zone is 300 ℃, the heating temperature of a fifth zone is 285 ℃, the heating temperature of a sixth zone is 270 ℃, and the temperature of a spinning box body is 266 ℃;

(2) accurately metering the polyamide 510 melt through a melt distribution pipe to a spinning metering pump in a spinning box, uniformly distributing the polyamide 510 melt (melt) into a spinning assembly through an equal-length pipe, and spraying the mixed melt in the spinning assembly from a circular spinneret plate (the number of holes is 44 holes) at the bottom of the spinning assembly at high pressure to form fiber yarns;

(3) and the fiber filaments fall into a water bath at 33 ℃ for cooling and forming, are subjected to primary drawing, enter a near-boiling water bath (about 85 ℃) and then are subjected to secondary drawing, the two-stage drawing ratio is controlled to be 3.6, then the fiber filaments are wound to a square ring, are fully wound, are transferred to a steam pot at 110 ℃ for heat setting for 0.5 hour, and are finally transferred to a drying room at 50 ℃ for drying to obtain the polyamide 510 monofilaments.

EXAMPLE two (Polyamide 510 monofilament)

(1) taking 20kg of polyamide 510 slices in the second preparation example, drying, continuously feeding into a single-screw extruder, heating, extruding and melting to obtain a polyamide 510 melt, and controlling the single-screw extruder in a partition mode along the axial direction, wherein the first-zone heating temperature is 264 ℃, the second-zone heating temperature is 298 ℃, the third-zone heating temperature is 298 ℃, the fourth-zone heating temperature is 298 ℃, the fifth-zone heating temperature is 280 ℃, the sixth-zone heating temperature is 266 ℃, and the spinning box temperature is 260 ℃;

(3) and the fiber filaments fall into a 38 ℃ water bath for cooling and forming, are subjected to primary drawing, enter a near-boiling water bath, are subjected to secondary drawing, are controlled to be 3.5 in the ratio, are wound onto a square ring, are fully wound, are transferred into a 100 ℃ steam pot for heat setting, and are finally transferred into a drying room for drying to obtain the polyamide 510 monofilaments.

EXAMPLE three (Polyamide 510 monofilament)

In this example, the same operation as in example two was performed except that the draft ratio was adjusted to 4.5 in example two, and the specific steps were as follows:

(3) and the fiber filaments fall into a 38 ℃ water bath for cooling and forming, are subjected to primary drawing, enter a near-boiling water bath, are subjected to secondary drawing, are controlled to have a draft ratio of 4.5, are wound onto a square ring, are fully wound, are transferred to a 100 ℃ steam pot for heat setting, and are finally transferred to a drying room for drying to obtain the polyamide 510 monofilaments.

EXAMPLE four (Polyamide 510 monofilament)

(1) taking 20kg of polyamide 510 slices in the third preparation example, drying, continuously feeding into a single-screw extruder, heating, extruding and melting to obtain a polyamide 510 melt, wherein the single-screw extruder is controlled in a partition mode along the axial direction, the first zone heating temperature is 272 ℃, the second zone heating temperature is 305 ℃, the third zone heating temperature is 305 ℃, the fourth zone heating temperature is 305 ℃, the fifth zone heating temperature is 290 ℃, the sixth zone heating temperature is 271 ℃ and the spinning box temperature is 268 ℃;

(3) and the fiber filaments fall into a water bath at 33 ℃ for cooling and forming, are subjected to primary drawing, enter a near-boiling water bath (about 85 ℃) and then are subjected to secondary drawing, the two-stage drawing ratio is controlled to be 3.8, then the fiber filaments are wound to a square ring, are fully wound, are transferred to a steam pot at 110 ℃ for heat setting for 0.5 hour, and are finally transferred to a drying room at 50 ℃ for drying to obtain the polyamide 510 monofilaments.

EXAMPLE five (Polyamide 510 monofilament)

(1) 20kg of polyamide 510 slices in the fourth preparation example are dried and then continuously fed into a single-screw extruder to be heated, extruded and melted into a polyamide 510 melt, the single-screw extruder is controlled in a partition mode along the axial direction, the first zone heating temperature is 275 ℃, the second zone heating temperature is 305 ℃, the third zone heating temperature is 310 ℃, the fourth zone heating temperature is 308 ℃, the fifth zone heating temperature is 295 ℃, the sixth zone heating temperature is 280 ℃, and the spinning box temperature is 275 ℃;

(3) and the fiber filaments fall into a water bath at 33 ℃ for cooling and forming, are subjected to primary drawing, enter a near-boiling water bath (about 85 ℃) and then are subjected to secondary drawing, the two-stage drawing ratio is controlled to be 4.9, then the fiber filaments are wound to a square ring, are fully wound, are transferred to a steam pot at 110 ℃ for heat setting for 0.5 hour, and are finally transferred to a drying room at 50 ℃ for drying to obtain the polyamide 510 monofilaments.

EXAMPLE six (Polyamide 511 monofilament)

(1) Taking 20kg of polyamide 511 slices in the fifth preparation example, drying, continuously feeding into a single-screw extruder, heating, extruding and melting to obtain a polyamide 511 melt, and controlling the single-screw extruder in a partition manner along the axial direction, wherein the first-zone heating temperature is 268 ℃, the second-zone heating temperature is 300 ℃, the third-zone heating temperature is 298 ℃, the fourth-zone heating temperature is 298 ℃, the fifth-zone heating temperature is 282 ℃, the sixth-zone heating temperature is 268 ℃ and the spinning box temperature is 265 ℃;

(2) accurately metering a polyamide 510 melt through a melt distribution pipe to a spinning metering pump in a spinning box, uniformly distributing the polyamide 511 melt (melt) to a spinning assembly through an equal-length pipe, and spraying the mixed melt in the spinning assembly from a circular spinneret plate (the number of holes is 44 holes) at the bottom of the spinning assembly at high pressure to form fiber yarns;

(3) and the fiber filaments fall into a water bath at 33 ℃ for cooling and forming, are subjected to primary drawing, enter a near-boiling water bath (about 85 ℃) and then are subjected to secondary drawing, the two-stage drawing ratio is controlled to be 3.8, then the fiber filaments are wound to a square ring, are fully wound, are transferred to a steam pot at 110 ℃ for heat setting for 0.5 hour, and are finally transferred to a drying room at 50 ℃ for drying to obtain the polyamide 511 monofilaments.

EXAMPLE seven (Polyamide 512 monofilament)

In this example, the same operation as in example six was carried out except that the polyamide 511 in example six was changed to the polyamide 512 in preparation example six, and the specific steps were as follows:

(1) taking 20kg of polyamide 512 chips in the sixth preparation example, drying, continuously feeding into a single-screw extruder, heating, extruding and melting to obtain a polyamide 511 melt, and controlling the single-screw extruder in a partition manner along the axial direction, wherein the first zone heating temperature is 268 ℃, the second zone heating temperature is 300 ℃, the third zone heating temperature is 298 ℃, the fourth zone heating temperature is 298 ℃, the fifth zone heating temperature is 282 ℃, the sixth zone heating temperature is 268 ℃ and the spinning box temperature is 265 ℃;

(3) and the fiber filaments fall into a water bath at 33 ℃ for cooling and forming, are subjected to primary drawing, enter a near-boiling water bath (about 85 ℃) and then are subjected to secondary drawing, the two-stage drawing ratio is controlled to be 3.8, then the fiber filaments are wound to a square ring, are transferred to a steam pot with 110 rolls after being fully wound for heat setting for 0.5 hour, and are finally transferred to a drying room at 50 ℃ for drying to obtain the polyamide 511 monofilaments.

EXAMPLE eight (Polyamide 513 monofilament)

In this example, the same operation as in example six was carried out except that the polyamide 511 in example six was changed to the polyamide 513 in preparation example seven, and the specific steps were as follows:

(1) taking 20kg of polyamide 513 slices in the preparation example seven, drying, continuously feeding the polyamide 513 slices into a single-screw extruder, and heating, extruding and melting the polyamide 511 slices to obtain a polyamide 511 melt, wherein the single-screw extruder is controlled in a partition mode along the axial direction, and the first-zone heating temperature is 268 ℃, the second-zone heating temperature is 300 ℃, the third-zone heating temperature is 298 ℃, the fourth-zone heating temperature is 298 ℃, the fifth-zone heating temperature is 282 ℃, the sixth-zone heating temperature is 268 ℃, and the spinning box body temperature is 265 ℃;

EXAMPLE nine (Polyamide 514 monofilament)

In this example, the same operation as in example six was carried out except that the polyamide 511 in example six was changed to the polyamide 514 in preparation example eight, and the specific steps were as follows:

(1) taking 20kg of polyamide 514 slices in preparation example eight, drying, continuously feeding into a single-screw extruder, heating, extruding and melting to obtain polyamide 511 melt, wherein the single-screw extruder is controlled in a partition mode along the axial direction, and the first zone heating temperature is 268 ℃, the second zone heating temperature is 300 ℃, the third zone heating temperature is 298 ℃, the fourth zone heating temperature is 298 ℃, the fifth zone heating temperature is 282 ℃, the sixth zone heating temperature is 268 ℃, and the spinning box temperature is 265 ℃;

EXAMPLE ten (Polyamide 516 monofilament)

In this example, the same operation as in example six was carried out except that the polyamide 511 in example six was changed to the polyamide 516 in preparation example nine, and the specific steps were as follows:

(1) taking 20kg of polyamide 516 chips in preparation example nine, drying, continuously feeding into a single-screw extruder, heating, extruding and melting to obtain a polyamide 511 melt, and controlling the single-screw extruder in a partition mode along the axial direction, wherein the first-zone heating temperature is 268 ℃, the second-zone heating temperature is 300 ℃, the third-zone heating temperature is 298 ℃, the fourth-zone heating temperature is 298 ℃, the fifth-zone heating temperature is 282 ℃, the sixth-zone heating temperature is 268 ℃ and the spinning box temperature is 265 ℃;

EXAMPLE eleven (Polyamide 518 monofilament)

In this example, the same operation as in example six was performed except that the polyamide 511 in example six was changed to the polyamide 518 in preparation example ten, and the specific steps were as follows:

(1) taking 20kg of polyamide 518 slices in the preparation example ten, drying, continuously feeding into a single-screw extruder, heating, extruding and melting to obtain polyamide 511 melt, and controlling the single-screw extruder in a partition mode along the axial direction, wherein the heating temperature of a first zone is 268 ℃, the heating temperature of a second zone is 300 ℃, the heating temperature of a third zone is 298 ℃, the heating temperature of a fourth zone is 298 ℃, the heating temperature of a fifth zone is 282 ℃, the heating temperature of a sixth zone is 268 ℃ and the temperature of a spinning box body is 265 ℃;

Comparative example 1

The comparative example provides a preparation method of a polyamide 66 monofilament, which comprises the following steps:

(1) taking 20kg of polyamide 66 slices in the first comparative preparation example, drying, continuously feeding the polyamide 66 slices into a single-screw extruder, and heating, extruding and melting the polyamide 66 slices to obtain a polyamide 66 melt, wherein the single-screw extruder is controlled in a partition mode along the axial direction, the first-zone heating temperature is 280 ℃, the second-zone heating temperature is 298 ℃, the third-zone heating temperature is 300 ℃, the fourth-zone heating temperature is 305 ℃, the fifth-zone heating temperature is 295 ℃, the sixth-zone heating temperature is 292 ℃, and the spinning box temperature is 285 ℃;

(2) accurately metering the polyamide 66 melt through a melt distribution pipe to a spinning metering pump in a spinning box, uniformly distributing the polyamide 66 melt (melt) into a spinning assembly through an equal-length pipe, and spraying the mixed melt in the spinning assembly from a circular spinneret plate (the number of holes is 44 holes) at the bottom of the spinning assembly at high pressure to form fiber yarns;

(3) and the fiber filaments fall into a water bath at 33 ℃ for cooling and forming, are subjected to primary drawing, enter a near-boiling water bath (about 85 ℃) and then are subjected to secondary drawing, the two-stage drawing ratio is controlled to be 3.8, then the fiber filaments are wound to a square ring, are fully wound, are transferred to a steam pot at 110 ℃ for heat setting for 0.5 hour, and are finally transferred to a drying room at 50 ℃ for drying to obtain the polyamide 66 monofilament.

Comparative example II

The comparative example provides a method for preparing polyamide 612 monofilament, which comprises the following steps:

(1) taking 20kg of polyamide 612 slices in the second comparative preparation example, drying, continuously feeding into a single-screw extruder, heating, extruding and melting to obtain a polyamide 612 melt, wherein the single-screw extruder is controlled in a partition mode along the axial direction, and the first zone heating temperature is 275 ℃, the second zone heating temperature is 302 ℃, the third zone heating temperature is 302 ℃, the fourth zone heating temperature is 302 ℃, the fifth zone heating temperature is 285 ℃, the sixth zone heating temperature is 272 ℃, and the spinning box temperature is 268 ℃;

(2) accurately metering the polyamide 612 melt through a melt distribution pipe to a spinning metering pump in a spinning box, uniformly distributing the polyamide 612 melt (melt) into a spinning assembly through an equal-length pipe, and spraying the mixed melt in the spinning assembly from a circular spinneret plate (the number of holes is 44 holes) at the bottom of the spinning assembly at high pressure to form fiber yarns;

(3) and the fiber filaments fall into a water bath at 33 ℃ for cooling and forming, are subjected to primary drawing, enter a near-boiling water bath (about 85 ℃) and then are subjected to secondary drawing, the two-stage drawing ratio is controlled to be 3.8, then the fiber filaments are wound to a square ring, are fully wound, are transferred to a steam pot at 110 ℃ for heat setting for 0.5 hour, and are finally transferred to a drying room at 50 ℃ for drying to obtain the polyamide 612 monofilaments.

The process parameters of the preparation methods of examples one to eleventh and comparative examples one to two are shown in table 4. The properties of the polyamide monofilaments obtained in examples one to eleventh and comparative examples one to two are shown in table 5.

Table 4 is a table of process parameters of the manufacturing methods of examples one to ten and comparative examples one and two

Table 5 shows properties of the polyamide monofilaments obtained in examples one to ten

As can be seen from the above table, the initial modulus of the polyamide monofilament (using odd-numbered carbon atom monomers as production raw materials) obtained in each example of the present invention is lower than that of the conventional polyamide 66 monofilament and polyamide 612 monofilament (using even-numbered carbon atom monomers as production raw materials) and the bending resilience is higher than that of the conventional polyamide 66 monofilament and polyamide 612 monofilament, which indicates that the polyamide monofilament obtained in each example of the present invention not only has good softness, but also has good lodging resistance, and can be applied in the field requiring low initial modulus and high bending resilience.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.

Claims

1. The polyamide monofilament is prepared from at least polyamide resin, wherein the viscosity number of the polyamide resin is 135-180 mL/g;

the production raw materials of the polyamide resin at least contain 1, 5-pentanediamine and aliphatic long carbon chain dibasic acid; the number of carbon atoms of the aliphatic long carbon chain dibasic acid is 10-18; the initial modulus of the polyamide monofilament is 2600-3279 MPa; the bending resilience of the polyamide monofilament is 66.1-80.1; the diameter of the polyamide monofilament is 0.15-0.35 mm.

2. Polyamide monofilament according to claim 1, characterized in that: the raw materials for producing the polyamide monofilament contain other constituent polymers and/or auxiliaries.

3. Polyamide monofilament according to claim 1, characterized in that: the polyamide resin contains polyamide and additive, and the polyamide is selected from any one or more of polyamide 510, polyamide 511, polyamide 512, polyamide 513, polyamide 514, polyamide 516 and polyamide 518.

4. Polyamide monofilament according to claim 3, characterized in that: the addition amount of the polyamide is not less than 50% of the total weight of the polyamide resin.

5. Polyamide monofilament according to claim 3, characterized in that: the addition amount of the polyamide is not less than 70% of the total weight of the polyamide resin.

6. Polyamide monofilament according to claim 3, characterized in that: the additive is added in an amount of not more than 50% by weight based on the total weight of the polyamide resin.

7. Polyamide monofilament according to claim 3, characterized in that: the additive is added in an amount of not more than 30% by weight based on the total weight of the polyamide resin.

8. Polyamide monofilament according to any one of claims 1 to 7, characterized in that: the polyamide resin has an amino-terminated group content of 5 to 100 mol/ton.

9. Polyamide monofilament according to any one of claims 1 to 7, characterized in that: the content of the terminal amino groups of the polyamide resin is 10-70 mol/ton.

10. Polyamide monofilament according to any one of claims 1 to 7, characterized in that: the content of the terminal amino groups of the polyamide resin is 20-60 mol/ton.

11. Polyamide monofilament according to any one of claims 1 to 7, characterized in that: the diameter of the polyamide monofilament is 0.1-3.0 mm.

12. Polyamide monofilament according to any one of claims 1 to 7, characterized in that: the breaking strength of the polyamide monofilament is more than or equal to 4.5N.

13. Polyamide monofilament according to any one of claims 1 to 7, characterized in that: the breaking strength of the polyamide monofilament is more than or equal to 8N.

14. Polyamide monofilament according to any one of claims 1 to 7, characterized in that: the elongation at break of the polyamide monofilament is 10-63%.

15. Polyamide monofilament according to any one of claims 1 to 7, characterized in that: the elongation at break of the polyamide monofilament is 18-55%.

16. Polyamide monofilament according to claim 1, characterized in that: the polyamide monofilament is used as a brush filament of a brushing tool, which is a toothbrush or a brushing brush.

17. A process for the preparation of polyamide monofilaments according to any of claims 1 to 16, characterized in that: the method comprises the following steps: carrying out spinning, cooling and forming, drafting and winding and shaping on the dried polyamide resin to obtain polyamide monofilaments;

the viscosity number of the polyamide resin is 135-180 mL/g;

the drawing step includes: and (3) taking the cooled and formed fiber filaments, performing primary drafting, then entering a near-boiling water bath, and performing secondary drafting, wherein the secondary drafting ratio is controlled to be 2-7, and the secondary drafting ratio is the ratio of the secondary drafting to the primary drafting.

18. The method of claim 17, wherein: the preparation method of the polyamide contained in the polyamide resin comprises the following steps:

19. The production method according to claim 17 or 18, characterized in that: the spinning process comprises the following steps: and slicing, heating, melting and extruding the dried polyamide resin, feeding the polyamide resin into a spinning assembly, and carrying out high-pressure spinning to form fiber yarns.

20. A washing and brushing tool is characterized in that: the filaments on the brush head are made of polyamide monofilaments according to any one of claims 1 to 7.

21. A brushing device as claimed in claim 20, wherein: the brushing tool is a toothbrush or a brushing brush.