JP2940163B2 - Polyester monofilament - Google Patents

Description

TECHNICAL FIELD The present invention provides excellent hydrolysis resistance and water repellency, oil repellency,
The present invention relates to a polyester filament having antifouling properties, and more particularly to a polyester monofilament which is suitably used as a constituent yarn of a papermaking dryer canvas having more excellent hydrolysis resistance and antifouling properties than conventional products.

Background Art Polyester filaments have excellent tensile strength, acid resistance,
Dryer canvas for paper making because of its dimensional stability,
It has been widely used for papermaking wires, various brushes, brushes, printing screen gauze, fishing line and the like. However,
For applications that are used under conditions that are easily hydrolyzed, such as high temperature and humidity, for example, when used as a constituent yarn for a papermaking dryer canvas, it is added to the stock solution of the papermaking in parallel with the deterioration during use and the decrease in strength. Various types of papermaking raw materials, such as fillers, sizing agents, and paper strength enhancers, and dirt from other materials accumulate and accumulate, which limits the use period and use conditions, and necessitates frequent cleaning of the canvas. It had the drawbacks such as. Therefore, various proposals have been made to improve the disadvantages of these polyester filaments.

As an example of a means for improving hydrolysis resistance,
Polyester monofilaments in which a specific amount of a polyolefin such as polyethylene, polypropylene, polybutene, poly-4-methylpentene-1, and polystyrene is added to polyester are known (JP-A-61-136923). Monofilaments, for example, monofilaments made of polyethylene terephthalate containing polyethylene are not practical because of low strength and high hydrolysis resistance.

There is also known a method for improving the hydrolysis resistance of polyester by adding a carbodiimide compound. For example, a method of adding a mono- or bis-carbodiimide compound and kneading and spinning in a short time to form a polyester filament containing no unreacted carbodiimide (Japanese Patent Laid-Open No. 50-95517); (Japanese Patent Application Laid-Open No. 38-15220), and a polyester monofilament for papermaking canvas in which a specific carbimide compound is left unreacted in a specific amount of polyester (Japanese Patent Application Laid-Open No. 38-15220). JP-A-58-23916), and a method for producing an industrial polyester filament to which a specific carbodiimide compound containing a specific amount of a phosphorus atom is added to a polyester (JP-A-58-23915).

On the other hand, various proposals have been made as a technique for improving the spinnability of polyester fibers. For example, a technology for treating textile products with a fluorine-containing compound (Japanese Patent Laid-Open No. 52-54)
No. 00, JP-A-58-46123), a core-sheath composite yarn having a fluororesin sheath (JP-A-53-31851), and a composition containing a perfluoroalkyl sulfonate (JP-A-53-31851).
59-66449), a fiber containing a fluororesin (JP-A-62-238822), a high knot strength monofilament containing oily or waxy polymonochlorofluoroethylene (JP-A-60-215813), Fibers containing fluororesin fine particles (JP-A-2-26919) are known. Also, in U.S. Pat.No.4,064,103, 2,2'-dimethyl-4,4'-dinitrodiphenylcarbodiimide,
Durable polybutylene terephthalate (hereinafter referred to as PBT) containing 0.1 to 5% by weight of 2,2 ', 6,6'-tetrachlorodiphenylcarbodiimide and 2,2'-dinitro-4,4'-dichlorodiphenylcarbodiimide Is proposed,
The description in the specification states that polytetrafluoroethylene (hereinafter, referred to as PTFE) can be mixed. U.S. Pat.No. 4,081,422 also contains carbodiimide or polycarbodiimide and other polymers.
A PBT copolymer-based composition has been proposed, and in the description of the specification, it is described that the sliding friction can be improved by mixing PTFE as another polymer. Also, U.S. Pat.
No. 246,992 discloses an unreacted mono- and / or biscarbodiimide compound containing not more than 30 ppm and an unreacted or polycarbodiimide having a carbodiimide group capable of reacting with at least one COOH terminal group in an amount of 0.05% by weight or more.
Polyester fibers and filaments having an OH terminal group of 3 meq / kg or less have been proposed, and the description in the specification states that PTFE can be mixed and that a new functional fabric can be obtained by adding PTFE. Also, in Swiss Patent No. 645658, a polyester composition made by mixing and dissolving a linear saturated polyester and a high molecular weight high fluorine-containing hydrocarbon compound is proposed, and the terminal carboxyl group of the polyester is blocked with carbodiimide. PTFE or PFA as a high molecular weight high fluorine-containing hydrocarbon compound
(Copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether) is shown. On the other hand, Japanese Unexamined Utility Model Publication No. Sho 61-43300 discloses a technique for imparting antifouling properties to a paper dryer canvas. There is proposed a technique for suppressing dirt on the surface. Also, JP-A-62-23
Japanese Patent No. 21094 proposes a technique of arranging a synthetic resin monofilament such as polyester containing 3 to 7% by weight of a fluororesin on a yarn constituting a surface of a canvas and extending in a warp direction. PT as fluororesin
A papermaking dryer canvas using a polyester monofilament containing FE is shown. However, these known techniques have not satisfied both the hydrolysis resistance and antifouling properties.

In recent years, the use conditions of polyester filaments used for papermaking dryer canvas have become increasingly severe,
For the purpose of preventing deterioration of paper productivity and paper quality, polyester monofilaments having even more excellent hydrolysis resistance and excellent antifouling properties have been required.

An object of the present invention is to provide a polyester filament having excellent hydrolysis resistance and antifouling property, which is useful as a papermaking dryer canvas or the like.

DISCLOSURE OF THE INVENTION The object of the present invention is achieved by the following configurations.

The terminal carboxyl group concentration is 10 equivalents / 10 ⁶ g or less, the carbodiimide compound contains 0.005% by weight or more and 1.5% by weight or less in the state of the final reaction, and tetrafluoroethylene and ethylene are main components. Polyester monofilament containing 0.01% by weight or more and 30% by weight or less of a copolymer.

 Hereinafter, the present invention will be described.

The polyester of the present invention is preferably one mainly composed of polyethylene terephthalate (hereinafter referred to as PET) and polybutylene terephthalate, and PET is more preferable. A part of the dicarboxylic acid component is isophthalic acid, 2,6-naphthalene. Dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, sebacic acid, dimer acid, sulfonic acid metal salt-substituted isophthalic acid may be replaced, and part of the glycol component may be diethylene glycol, neopentyl glycol, 1,4- It may be replaced with cyclohexanediol, 1,4-cyclohexanedimethanol, polyalkylene glycol or the like. Further, a small amount of a chain branching agent such as pentaerythritol, trimethylolpropane, trimellitic acid, trimesic acid, and boric acid can be used in combination. In addition, various inorganic particles such as titanium oxide, silicon oxide, calcium carbonate, silicon nitride, clay, talc, kaolin, zirconic acid and the like, crosslinked polymer particles, various metal particles and the like, as well as conventionally known antioxidants, metals Ion sequestering agents, ion exchange agents, anti-coloring agents, light-proofing agents, flame retardants, clathrate compounds, antistatic agents, various colorants,
Waxes, silicone oil, various fluorine-based surfactants, various reinforcing fibers, and the like may be added. The polyester of the present invention may be a blend of two or more of the above modified polyester resin, further polyamide,
Polyester amide, epoxy resin, silicone resin,
A blend of resins such as polyolefin resin, various rubbers, polycarbonate, polyurethane, and polyacrylate may be used.

Polyester monofilament of the present invention should be a terminal carboxyl group concentration is less than 10 equivalents / polyurethane 10 ⁶ g. Here, the terminal carboxyl group concentration is Phol
And ANALYTICAL CHEMISTRY Vol. 26, page 1614. Terminal carboxyl group concentration is unfavorably 10 equivalents / polyurethane 10 exceeds ⁶ g When hydrolysis resistance levels low monofilament.

The terminal carboxyl group concentration of the present invention to obtain a 10 equivalents / polyester 10 ⁶ g or less of the polyester monofilaments, for example, a polyester terminal carboxyl group concentration is more than 10 equivalents / polyester 10 ⁶ g, known in the molten state of the polyester Phenylglycidyl ether, N
-Glycidyl phthalimide, o-phenyl phenyl glycidyl ether, ethylene oxide, an epoxy compound such as propylene oxide or a known compound such as oxazoline can be obtained by reacting an appropriate amount, but the polyester monofilament of the present invention is in an unreacted state the carbodiimide compound 0.005% by weight or more, since those containing 1.5 wt% or less, the terminal carboxyl group concentration of 10 one or more in one molecule to obtain equivalent / polyurethane 10 ⁶ g or less of a polyester monofilament It is advantageous to use a carbodiimide compound having a carbodiimide group. In other words, from the terminal carboxyl group concentration of the raw material polyester and the reaction conditions,
It is advantageous to add the carbodiimide compound to the polyester after the reaction in an amount such that the unreacted residual carbodiimide compound remaining in the polyester after the reaction has a concentration of 0.005% by weight or more and 1.5% by weight or less.

The intrinsic viscosity of the polyester monofilament of the present invention may usually be 0.6 or more. Here, the intrinsic viscosity is the intrinsic viscosity obtained from the viscosity measured at 25 ° C. in an orthochlorophenol solution, and is represented by [η].

In order to more efficiently exhibit the effects of the present invention, a phosphorus compound is contained in the polyester as a phosphorus atom in an amount of 50%.
It is preferred that the content be less than ppm and within the following range.

5 × 10 ⁻³ ≦ P ≦ M + 8 × 10 ⁻³ (wherein P is the mole% of phosphorus atoms with respect to the dibasic acid constituting the polyester, M is a metal in the polyester resin, It is a mol% based on the dibasic acid constituting the polyester of one or more metal atoms selected from Group VII and Group VIII and from the third and fourth cycles.
M may be 0).

The carbodiimide compound contained in the polyester monofilament of the present invention includes one carbodiimide compound per molecule.
Compounds having one or more carbodiimide groups are preferred, for example, N, N'-di-o-triylcarbodiimide, N, N'-diphenylcarbodiimide, N, N'-dioctyldecylcarbodiimide, N, N ' -Di-2,6-dimethylphenylcarbodiimide, N-triyl-N'-cyclohexylcarbodiimide, N, N'-di-2,6-diisopropylphenylcarbodiimide (hereinafter referred to as TIC), N, N'-di-2 , 6-Di-tert.-butylphenylcarbodiimide, N-triyl-N'-phenylcarbodiimide, N, N'-di-p-nitrophenylcarbodiimide, N, N'-di-p-aminophenylcarbodiimide,
N, N'-di-p-hydroxyphenylcarbodiimide,
N, N'-di-cyclohexylcarbodiimide, N, N'-di-p-triylcarbodiimide, p-phenylene-bis-di-o-triylcarbodiimide, p-phenylene-
Examples include bis-dicyclohexylcarbodiimide, hexamethylene-bis-dicyclohexylcarbodiimide, ethylene-bis-diphenylcarbodiimide, and aromatic polycarbodiimide represented by the following general formula.

(Wherein R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and n represents an integer of 2 to 20). One or more of these carbodiimide compounds are arbitrarily selected. Compounds having an aromatic skeleton are preferable from the viewpoint of stability after addition to the polyester, and TIC, N, N'-di-2,6-di-tert.-butylphenylcarbodiimide, N N, N'-di-2,6-dimethylphenylcarbodiimide, N, N'-di-o-triylcarbodiimide and the like are more preferred. Particularly, TIC is preferred in terms of reactivity.

0.005% by weight of the unreacted carbodiimide compound contained in the polyester monofilament of the present invention.
It is necessary that the content be 1.5% by weight or less, and more preferably 0.01% by weight or more and 1.2% by weight or less. 0.005% by weight
If less, hydrolysis resistance is insufficient, and 1.5% by weight
If it is larger, the physical properties of the monofilament are impaired, which is not preferable.

Here, the content of the unreacted carbodiimide compound in the polyester monofilament referred to in the present invention is measured by the following method.

That is, 100 g of polyester monofilament
It was chopped to a size of 3 mm and treated in 500 cc of chloroform at the boiling point of chloroform for 8 hours. After the treatment, the polyester monofilament was removed, and chloroform was distilled off. 50 cc of methanol was added to the obtained extract, and the insoluble matter was separated by filtration. Most of the methanol was distilled off from the methanol solution under reduced pressure, and concentrated to such an extent that no extract was precipitated. The methanol solution was analyzed by gas chromatography to quantify the carbodiimide compound.

The mixing and reaction of the carbodiimide compound and the polyester are carried out by adding the carbodiimide compound to the molten polyester immediately after the completion of the polycondensation reaction, and stirring and reacting the mixture. Or a method of kneading and reacting with an extruder, etc., continuously adding the liquid carbodiimide compound to the polyester with an extruder,
Kneading and reaction can be performed.

The polyester monofilament of the present invention contains a random copolymer (hereinafter, referred to as ETFE) containing tetrafluoroethylene and ethylene as main components.

As BTFE, as components other than tetrafluoroethylene and ethylene, monochlorotrifluoroethylene,
One or more components selected from perfluoroacrylate, perfluoroalkyl acrylate, perfluoroalkyl vinyl ether, hexafluoropropylene, vinylidene fluoride and the like may be copolymerized at about 0.1 to 10% by weight.

The upper limit of the fluorine atom content of the ETFE is about 69% by weight in the case of a 1: 1 copolymer of ethylene and tetrafluoroethylene. In order to obtain decomposability, it is preferred that the composition contains at least 40% by weight or more of fluorine atoms. More preferably, when ETFE containing fluorine atoms of 42% by weight or more, even more preferably 46% by weight or more is used, a polyester monofilament having more excellent antifouling property and hydrolysis resistance as the object of the present invention is obtained. It is preferred because it can be obtained.

Here, the above-mentioned fluorine content in the ETFE is determined by measuring the fluorescent X-ray intensity of fluorine atoms of a plate on which an ETFE chip is press-molded, using a full-automatic fluorescent X-ray analyzer (3080E2 type, manufactured by Rigaku). It is determined by comparing with the fluorescent X-ray intensity of fluorine atoms obtained from polytetrafluoroethylene (fluorine atom content: 76.0% by weight).

Further, as the ETFE, an object of the present invention is to use an ETFE chip, a component containing a fluorine atom extracted using a hexafluoroisopropanol solvent, of 20 ppm or more based on the amount of the FETE chip before extraction. It is possible to obtain a polyester monofilament having more excellent antifouling property and heat resistance. The reason for this is not clear, but it is presumed that the component containing a fluorine atom of ETFE that is extracted with hexafluoroisopropanol elutes and diffuses into the polyester.

The amount of the extracted component of the ETFE chip and the confirmation that the extracted component contained a fluorine atom were confirmed by the following method.

100 g of ETFE chips in hexafluoroisopropanol 20
Together with 0 g, the mixture was charged into a flask equipped with a reflux condenser, a stirrer, and a heating device, extracted at normal pressure at the boiling point of hexafluoroisopropanol for 7 hours, and then cooled to room temperature. Then, after filtering through a 17G-4 glass filter, the mixture was further filtered through a filter having a mesh size of 1 micron. Further, the filtrate was centrifuged at 1600 rpm, and the supernatant was decanted to remove foreign substances, thereby obtaining hexafluoroisopropanol. A solution was obtained. Next, hexafluoroisopropanol in the solution was evaporated, and further vacuum-dried at room temperature to obtain an extracted component. Infrared absorption analysis of this extracted component was performed, and it was confirmed that the extracted component contained a fluorine atom by absorption of the obtained infrared absorption spectrum by C-F stretching vibration of 1,440 to 1,000 cm ^-1 .

The content of ETFE in polyester monofilament is 0.
It is necessary that the content is not less than 01% by weight and not more than 30% by weight.
When the amount is less than 0.01% by weight, not only the effect of improving the hydrolysis resistance becomes insufficient, but also the antifouling property is not exhibited, and when the amount is more than 30% by weight, the physical properties of the polyester monofilament are impaired. Particularly preferably, the content is 0.5% by weight or more and 15% by weight or less.

Addition and kneading of ETFE to polyester can be performed by adding and kneading ETFE to polyester in the molten state during or immediately after the polycondensation reaction.
And kneading with an extruder.

ET in the polyester monofilament of the present invention
FE is present in a dispersed state in the polyester. The dispersion state of the ETFE in the polyester can be various forms such as a particle state and a fibril state, but the ETFE is present in a fibril form having an average length of 10 μm or more and an average diameter of 0.15 μm or more and 2 μm or less. Those are preferred because of their superior steam heat resistance, which is one of the objects of the present invention.

Polyester monofilaments containing ETFE dispersed in fibrils having an average length of 10 μm or more and an average diameter of 0.15 μm or more have a melt flow rate of 2 at a temperature of 297 ° C. and a load of 5 kg according to the method of ASTM test method D3159. ETFE of up to 40 g / 10 min, preferably 3 to 25 g / 10 min, is kneaded with a carbodiimide compound in a uniaxial extruder, and then melt-spun and drawn by a conventional method.

ETFE in the above polyester monofilament
The in dispersed state observation, the monofilament, the ultra thin cut in parallel to the vertical direction and the fiber axis to the fiber axis using a diamond cutter was stained with RuO _4, JEOL transmission electron microscope JEM-1200EX A photograph was taken at a magnification of 5000 to 40,000 times using a mold, and the dispersion diameter and the dispersion length of the dispersed solid on the obtained photograph were measured. The dispersion length of ETFE in the polyester monofilament is about 25.
The exact length of solids above μm cannot be measured with a transmission electron microscope due to the limited field of view and the difficulty in obtaining ultrathin sections completely parallel to the fiber axis. Near impossible.

For the purpose of compensating for this drawback, another method for determining the dispersibility in the length direction is a method lacking in quantitativeness.
The monofilament cut to 2 cm was inserted into the o-
It is possible to adopt a method in which it is poured into chlorophenol and heated to about 100 ° C. to gently dissolve and remove the PET component, and observe ETFE insoluble in o-chlorophenol. According to this method, a relatively short FET, such as less than 10 μm, cannot be observed because it is dispersed in o-chlorophenol.
The relatively long ETFE of μm or more has a cutting length of 1-2 cm before melting.
Can be observed as an aggregate of fibrils close to.

In the production of the polyester filament of the present invention, as described above, a polyester containing a carbodiimide compound and ETFE is extruded from a spinneret through a polymer streamline exchanger, a filtration layer, etc. installed at the extruder tip, and cooled. -It can be manufactured by a known method such as stretching and heat setting.

The polyester monofilament of the present invention has a carbodiimide compound-containing polyester that does not contain ETFE as a core, and a core-sheath composite monofilament that has a sheath containing a polyester containing ETFE and a carbodiimide compound, and both the core and sheath contain ETFE and a carbodiimide compound. The core-sheath composite monofilament may be a polyester having different ETFE contents in the core and the sheath.

The polyester monofilament of the present invention is a continuous yarn composed of one single yarn, and may have any cross-sectional shape such as a circle, a flat, a square, a triangle, a polygon having five or more corners, a multilobe, a dog horn, and a cocoon. When the monofilament is a warp yarn of a yarn-forming dryer canvas, a flat cross-section yarn is preferably used from the viewpoint of improving antifouling properties and flatness of the canvas. The term “flat” in the present invention refers to an ellipse or a rectangle, but includes not only an exact ellipse or a rectangle defined mathematically but also a shape that is substantially similar to an ellipse or a rectangle, for example, a shape obtained by rounding a square of a rectangle. It is a thing. Also, in the case of an ellipse, the major axis (LD) and the minor axis (SD) that intersect at right angles at the center of the ellipse have a relationship satisfying the following. It is preferable that the short turn (SD) satisfies the following expression.

1.2 ≦ LD / SD ≦ 6 The length of the line segment passing through the center of gravity of the yarn cross section is 0.10 to 2.5 mm
Is preferable.

In addition, as the cross-sectional shape of the polyester monofilament of the present invention, in addition to the above-mentioned flat cross section, a square, a triangle, a polygon having five or more angles, a multi-leaf shape, a dog horn shape, and a cocoon shape can be suitably adopted. These specific examples are shown in FIG.
The cross-sectional shape of the polyester monofilament of the present invention,
In the case of a square, a triangle, a polygon having five or more angles, and a multi-leaf shape, when the monofilament is used as a papermaking dryer canvas, deformation during use of the canvas can be suppressed. Further, when the cross-sectional shape of the polyester monofilament of the present invention is a dog horn shape or a cocoon shape, when the monofilament is used as a papermaking dryer canvas, the permeability of the canvas is adjusted, and the paper in the dryer is adjusted. The distribution of the degree of drying becomes uniform, and a paper having a good finish can be obtained.

When the diameter of the monofilament is smaller than 0.10 mm, when the monofilament is used under severe conditions such as high temperature and high humidity like a papermaking dryer canvas, the monofilament deteriorates quickly and is not preferable. Although the reason for this is not clear, the ETFE resin in the monofilament and the compound containing a fluorine atom eluted from the ETFE resin into the PET portion prevent the water that hydrolyzes PET from penetrating from the surface of the filament into the interior. Synergistically as the depth increases. However, since the effect of preventing moisture from entering the surface of the yarn and the portion relatively close to the surface layer is not sufficient, the hydrolysis of PET on the surface of the yarn and the portion relatively close to the surface layer proceeds faster than inside the monofilament. Accordingly, when the diameter of the monofilament is smaller than 0.10 mm, the PET portion in which hydrolysis has not progressed as compared to the surface layer portion that governs high strength under severe conditions such as high temperature and high humidity of the monofilament. Probably because the ratio becomes low. On the other hand, if the diameter of the monofilament is larger than 2.5 mm, it is difficult to weave the monofilament on a papermaking dryer canvas or the like, which is not preferable.

Further, the monofilament may be provided with a known water / oil repellent, lubricant, or the like on the surface.

The polyester monofilament of the present invention has both better hydrolysis resistance and better antifouling properties than conventional ones.

The reason that the hydrolysis resistance is more excellent than that of the conventional one is that the unreacted carbodiimide compound and ETFE contained in the polyester monofilament of the present invention, and the carboxyl end group concentration of polyester which is a substrate constituting the monofilament are low. This is considered to be a synergistic effect of three factors. The hydrolysis of the polyester is caused by the invading moisture and heat, the hydrolysis is promoted by the carboxyl end groups of the polyester, and the hydrolysis of the polyester increases the carboxyl end groups of the polyester, resulting in the hydrolysis of the polyester. Further acceleration is a well-known fact. Further, the carbodiimide compound has a function of eliminating the ability of the carboxyl terminal group to promote hydrolysis of the polyester by reacting with the carboxyl terminal group of the polyester. However, carbodiimide compounds also have the property of reacting with moisture at high temperatures and losing reactivity with the carboxyl end groups of the polyester. On the other hand, ETFE having excellent water repellency has a function of suppressing the intrusion of moisture into the polyester by being finely dispersed in the polyester. However, the hydrolysis resistance of the monofilament of the present invention is superior to the sum of the above-mentioned various factors that suppress the hydrolysis of the polyester. First, the polyester monofilament of the present invention suppresses the initial hydrolysis by lowering the carboxyl end group concentration of the polyester which has the action of promoting hydrolysis, and, because the carboxyl end group concentration is low, the carbodiimide compound is substantially It is easy to exist in the polyester in an unreacted state. In addition, by including ETFE in the polyester, the intrusion of water into the polyester is restricted, the hydrolysis of the polyester is further suppressed, the increase of the carboxyl end group is prevented, and the unreacted carbodiimide compound has a carboxyl end group or It suppresses consumption by reacting with moisture. Further, the presence of the unreacted carbodiimide compound in the polyester prevents the increase of the carboxyl end group in the polyester by reacting with the carboxyl end group generated by hydrolysis, thereby further improving the hydrolysis resistance of the polyester. I have. As described above, the reason that the hydrolysis resistance of the polyester monofilament of the present invention is more excellent than that of the conventional one is not the result of the above-mentioned three factors functioning independently, but the three factors interact with each other. This is due to a synergistic effect.

The polyester monofilament of the present invention is suitable as a raw yarn for a papermaking dryer canvas in producing medium-quality paper, newsprint, various paperboards, and the like. That is, by using the polyester monofilament of the present invention as a yarn for a papermaking dryer canvas, dirt and deterioration of the dryer canvas during papermaking are reduced, the paper quality is stabilized, and the cleaning cycle and life of the canvas are significantly extended. .

As described above, the polyester monofilament of the present invention is suitable for, for example, a papermaking dryer canvas and the like, and is a useful product having both excellent hydrolysis resistance and antifouling properties as compared with conventional products. .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a shape of a discharge hole for obtaining a monofilament having a substantially rectangular cross section in Example 1.

FIG. 2 is a specific example of the cross-sectional shape of the polyester monofilament of the present invention.

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

 In addition, the antifouling property evaluation of the Example was performed by the following method.

(1) Preparation of contaminated liquid Talc 1 part by weight Alkyl ketene dimer 0.5 part by weight Acrylamide 0.5 part by weight Water 98 parts by weight The above contaminated liquid is close to a composition consisting of dirt and water that usually adhere to a paper dryer canvas. It is.

(2) While stirring the adjusted contaminated liquid at 300 rpm, the weighed monofilament was immersed at a bath ratio of 1: 5000 for 5 seconds, and then immersed at 70 ° C.
The operation of stirring for 1 minute with was repeated 10 times to obtain a soiled sample.

(3) The sample to which dirt adhered was weighed, and the amount of dirt adhered was determined.

Example 1 Intrinsic viscosity 0.93, terminal carboxyl group concentration 20 equivalents / 10 ⁶ g
PET chips of antimony compound: 300 ppm of antimony compound by antimony atom and manganese compound by manganese atom as catalyst
60 ppm (0.021 mol% of manganese atom to terephthalic acid),
30 ppm of phosphorus compound by phosphorus atom (0.019 mol% by phosphorus atom)
Terephthalic acid) content, the amount of extractables extracted into hexafluoroisopropanol is 240 ppm, the content of fluorine atoms measured by fluorescent X-ray method is 48% by weight, and ASTM-D3
ETFE chips having a melt float of 9 g / 10 minutes measured at 297 ° C. and 5 kg under 195 ° C. according to 195 by weight ratio of PET
TIC as a carbodiimide compound was added to the PET / ETF blend chip mixed at a ratio of / ETFE = 100/6 at a weight ratio of PET chip / carbodiimide compound = 100 / 1.63 and supplied to the extruder inlet. The 300 ° C melt polymer kneaded at 300 ° C by melt-kneading at 300 ° C is spun from the discharge hole shown in Fig. 1 through a filtration layer in a spinning pack and a streamline exchanger ("Starics Mixer" of Chemis, USA) via a gear pump. Issued. After cooling the spun monofilament in a hot water bath at 80 ° C, it is stretched and heat-set by a total of 6 times according to a conventional method, and the yarn cross-sectional shape is substantially rectangular (long side 0.56 mm, short side 0.28 m
m) was obtained. Table 1 shows the strength, the terminal carboxyl group content, the TIC content, the evaluation results of the spinning resistance of the monofilament, and the strength retention when the monofilament was allowed to stand continuously in saturated steam at 120 ° C. for 10 days.

The dispersion of ETFE measured from a transmission electron micrograph of this monofilament was 0.23 μm in average diameter, and the average length of the fibrils confirmed was 15.4 μm. For reference, cut this monofilament to about 1.5 cm length,
Put in 15 cc of o-chlorophenol in a test tube, 105 ° C
For 30 minutes to dissolve the PET. A white substance of about 1.2 cm in length was present in o-chlorophenol in this test tube. The white matter was washed with clean o-chlorophenol and methanol and then observed with an optical microscope. As a result, the exact length of each fibril could not be measured because many fibrils were intertwined,
It was confirmed that the white matter was an aggregate of fibrils having a length of 10 μm or more, including many fibrils having a length of 180 μm or more.

Comparative Examples 1 and 2 For comparison, in Example 1, the case of a monofilament obtained in the same manner as in Example 1 except that no ETFE chip was added. Comparative Example 1 except that no TIC was added. The case of a monofilament obtained in the same manner as in Example 1 is shown in Table 1 as Comparative Example 2.

Examples 2 to 5, Comparative Examples 3 to 6 In Example 1, the mixing amount of ETFE chips was changed as shown in Table 1 (Examples 2, 3, Comparative Examples 3, 4). Table 1 shows the case of monofilaments obtained in the same manner as in Example 1 except that the amount of addition was changed as shown in Table 1 (Examples 4, 5 and Comparative Examples 5, 6).

Example 6 A case of the monofilament obtained in the same manner as in Example 1 except that the shape of the discharge hole was changed to a circle and the cross-sectional shape of the monofilament was changed to a circular cross-section having a diameter of 0.45 mm was used. It is shown in Table 2.

Example 7 In Example 1, FETE was changed to ETFE in which the amount of extractables extracted into hexafluoroisopropanol was 98 ppm and the content of fluorine atoms measured by a fluorescent X-ray method was 43% by weight. Table 2 shows the case of the monofilament obtained in the same manner as in Example 1.

Example 8 In Example 1, FETE was changed to ETFE having an extractable amount of 89 ppm extracted with hexafluoroisopropanol and a fluorine atom content of 41% by weight measured by a fluorescent X-ray method. Table 2 shows the case of the monofilament obtained in the same manner as in Example 1.

Example 9 In Example 1, except that FETE was changed to ETFE in which the amount of extractables extracted into hexafluoroisopropanol was 45 ppm and the content of fluorine atoms measured by a fluorescent X-ray method was 38% by weight. Table 2 shows the case of the monofilament obtained in the same manner as in Example 1.

Comparative Example 7 Table 2 shows a monofilament obtained in the same manner as in Example 1 except that the amount of FETE was changed to 8% by weight and TIC was not added.

Example 10 Table 2 shows the results of monofilaments obtained in the same manner as in Example 1 except that TIC was changed to N, N'-di-o-triylcarbodiimide. However, during this experiment, N, N'-di-
Intense fumes resulted from o-triylcarbodiimide.

Example 11 Table 2 shows the results of monofilaments obtained in the same manner as in Example 1 except that the phosphorus compound in the PET chip was changed to 60 ppm with phosphorus atoms.

Comparative Example 8 A monofilament obtained in the same manner as in Comparative Example 1 except that the shape of the discharge hole was changed to a circle and the cross-sectional shape of the monofilament was changed to a circular cross-section having a diameter of 0.45 mm. Table 2 shows the case of (1).

Example 12 In Example 1, ETFE was converted to 297 according to ASTM-D3159.
Melt flow rate measured at 5 ° C and 5kg is 45g / 10
Table 2 shows the results of the monofilaments obtained in the same manner as in Example 1 except that the monofilaments were changed. FTFE in this monofilament measured from transmission electron micrographs
Has an average diameter of 0.09 μm and an average length of 1.1 μm.

Example 13 In Example 6, the diameter of the monofilament was set to 0.05 mm.
Table 2 shows the results of the monofilaments obtained in the same manner as in Example 6 except that the conditions were changed to.

Example 14 Table 2 shows the results of the monofilament obtained in the same manner as in Example 1 except that TIC was changed to 0.81% by weight.

Example 15 In Example 1, the ETFE was 0.02 with respect to 100 parts by weight of PET.
Table 2 shows the results of monofilaments obtained in the same manner as in Example 1 except that the amount was changed to parts by weight.

Example 16 A twill weave canvas for a papermaking dryer was prepared using the monofilament having a flat cross section obtained in Example 1 as a warp and the monofilament having a circular cross section obtained in Example 6 as a weft. After attaching this canvas to the dryer of a neutral paper machine and using it for drying the paper at 140 ° C for 3 months,
The canvas was removed. A part of the canvas was cut out and subjected to ultrasonic cleaning for 1 hour in a mixed solution of water and acetone (1: 1 by volume) containing 0.3% by weight of polyoxyethylene alkyl ether. The adhesion amount of dirt determined from the difference in the weight of the canvas before and after washing was 0.8% by weight. The strong residual ratio of the warp of the canvas before washing was 84%.

Comparative Example 9 Example 16 was repeated except that the monofilament used for the warp was changed to the flat cross-section monofilament of Comparative Example 1 and the monofilament used for the weft was changed to the circular cross-section monofilament of Comparative Example 8 in Example 16. When carried out in the same manner as in the above, the stain adhesion amount was 2.1% by weight, and the strong residual ratio of the warp of the canvas before washing was 69%.

INDUSTRIAL APPLICABILITY The polyester monofilament of the present invention has even more excellent hydrolysis resistance and excellent antifouling properties than conventional ones. When used in applications that are easy to use, for example, in a paper-dryer canvas, the effect is great, for example, the use period can be extended more than before, and the cleaning cycle can be greatly extended.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) D01F 6/92 D21F 7/08

Claims (10)

(57) [Claims] 1. A at terminal carboxyl group concentration of 10 or less equivalents / polyester 10 ⁶ g, 0.005 wt% or more in the state of the end reaction carbodiimide compound, containing 1.5 wt% or less, and the tetrafluoroethylene and ethylene 0.01% by weight or more, 30% by weight of random copolymer as main constituent
Polyester monofilament contained below. 2. The polyester monofilament according to claim 1, wherein the polyester monofilament comprises a dispersion comprising a random copolymer containing tetrafluoroethylene as a main component and ethylene having an average length of 10 μm or more and an average diameter of 0.15 μm or more. . 3. A carbodiimide compound comprising N, N'-di-2,6-
3. The polyester monofilament according to claim 1, which is diisopropylphenylcarbodiimide. 4. A random copolymer containing tetrafluoroethylene and ethylene as main components has a fluorine atom of 40%.
The polyester monofilament according to any one of claims 1 to 3, which contains at least 1% by weight. 5. A random copolymer comprising tetrafluoroethylene and ethylene as main components, wherein a fluorine atom is
The polyester monofilament according to any one of claims 1 to 3, which contains 42% by weight or more. 6. A random copolymer containing tetrafluoroethylene and ethylene as main constituents has a fluorine atom.
The polyester monofilament according to any one of claims 1 to 3, which contains 46% by weight or more. 7. The method according to claim 1, wherein the random copolymer containing tetrafluoroethylene and ethylene as main components contains 20 ppm or more of a component extracted with hexafluoroisopropanol. Polyester monofilament. 8. The polyester monofilament according to claim 1, wherein the monofilament has a flat cross section. 9. The polyester monofilament according to claim 1, wherein the shortest line segment passing through the center of gravity of the cross section of the monofilament is 0.1 mm or more. 10. The polyester monofilament according to claim 1, which is used as a constituent yarn of a papermaking dryer canvas.