JPH0586507A - Polyester monofilament - Google Patents

Abstract

(57) [Summary] [Structure] A polyester monofilament containing 1% by weight or more and 40% by weight or less of a thermoplastic elastomer (excluding thermoplastic polyurethane). [Effect] It has excellent wear resistance against abrasion of calcium carbonate particles of neutral paper filler, and has necessary and sufficient yarn strength and stable wire diameter. Papermaking nets, filters, belt cloths, etc. It is useful as an industrial material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester monofilament having excellent abrasion resistance, and relates to a polyester monofilament useful as an industrial material such as a papermaking net, a filter and a belt cloth.

[0002]

2. Description of the Related Art Generally, thermoplastic polyesters such as polyethylene terephthalate have excellent mechanical properties and chemical properties, and have been widely used as molded articles such as fibers and films. However, when the polyester monofilament is used for contact with other materials such as particles, structures, etc. of metal, ceramics, plastics, etc. in industrial applications, the particles and structures are vulnerable to abrasion damage, and therefore the polyester monofilament is used. Nets and fabrics using monofilaments have a shortcoming that they have a short life as products. For example, in the paper industry,
Conventionally, acid paper has been mainly manufactured, but as the problem of deterioration of paper over time becomes more and more prominent, conversion to neutral paper has become popular. Along with the conversion from acid paper to neutral paper, the filler used for paper called filler has been changed from talc to calcium carbonate, but since calcium carbonate particles are harder than talc particles, they are used in the papermaking process. The mesh for paper making (hereinafter referred to as a wire) wears quickly, and in particular, the wire made of polyester monofilament has a short life as compared with the wire made of polyamide monofilament such as nylon 6. Nylon wire has the advantage that it is relatively hard to wear as mentioned above, but it has the fatal drawback that the dimensions of the wire change due to moisture during papermaking, which causes troubles in papermaking. Also in the above, improvement in abrasion resistance of a polyester monofilament wire having good dimensional stability has been desired.

Various proposals have hitherto been made to improve the abrasion resistance of polyester monofilaments.
For example, a polyester monofilament containing abrasive particles such as alumina powder, silicon carbide, and zirconia-based abrasive has a slight abrasion resistance improving effect, but the dispersion of the abrasive particles in the polyester is poor, so that the yarn quality is poor. Inferior or damage to the surface of various rollers and guides that come into contact with monofilaments and various textiles using monofilaments, such as the manufacturing process of monofilaments and the weaving process of various textiles using monofilaments, and paper machines. It had drawbacks. Further, Japanese Patent Application Laid-Open No. 63-42976 proposes a method of applying a hard coating film such as a polysiloxane coating material and a crosslinked acrylic coating material to the surface of the monofilament, but the surface coating film is easily removed. There was a problem in terms of durability. Further, Japanese Patent Application Laid-Open No. 2-80688 proposes a fabric for papermaking having improved abrasion resistance, which uses a monofilament in which a specific amount of thermoplastic polyurethane is contained in polyethylene terephthalate. The resin decomposes at a melt spinning temperature with polyethylene terephthalate, making spinning difficult, which poses a large industrial problem and is not practical.

[0004]

SUMMARY OF THE INVENTION The present invention is to provide a polyester monofilament which is free from the above-mentioned various drawbacks and which is useful as an industrial material such as a paper making net, a filter and a belt cloth, and which is excellent in abrasion resistance.

[0005]

The above-mentioned object of the present invention is to provide a thermoplastic elastomer in an amount of from 1% by weight to 40% by weight.
This can be achieved by a polyester monofilament containing: Hereinafter, the present invention will be described in detail. The polyester used to form the monofilament of the present invention is mainly composed of a difunctional component such as an aromatic dicarboxylic acid or its dialkyl ester and a glycol component, and is preferably composed mainly of polyethylene terephthalate. .. The polyester mainly composed of polyethylene terephthalate may be a homopolyester or a copolyester, and examples of the copolymerization component include adipic acid, sebacic acid, phthalic acid, naphthalene-2,6-dicarboxylic acid and 5-sodium. Dicarboxylic acid components such as sulfoisophthalic acid, trimellitic acid,
Polyvalent carboxylic acid components such as pyromellitic acid, oxycarboxylic acid components such as p-oxyethoxybenzoic acid, and tetramethylene glycol, hexamethylene glycol, diethylene glycol, propylene glycol, neopentyl glycol, polyoxyalkylene glycol, p-xylyl A diol component such as ren glycol, 1,4-cyclohexanedimethanol, and 5-sodium sulforesorcin may be contained.

The polyester monofilament of the present invention is a continuous yarn composed of one single yarn containing the above-mentioned polyester as a main component, and has a cross-sectional shape such as a circle, a triangle, a square or a regular polygon. From the viewpoint of improving wear resistance,
A round cross section is the most resistant to wear and is preferred. The diameter of the cross section can be appropriately selected depending on the application, but is 0.01 to 3 mm.
The range of is most often used. Although the required strength of the yarn varies depending on the use, it is preferably 3.0 g / denier or more for a paper making net.

The thermoplastic elastomer contained in the polyester monofilament of the present invention is a polymer showing rubber elasticity at room temperature and plasticity similar to that of thermoplastic at high temperature. For example, polystyrene is mainly used as a hard segment. , A styrene thermoplastic elastomer mainly composed of a block copolymer having polybutadiene or hydrogenated butadiene or polyisoprene as a soft segment, a polyolefin such as polypropylene or polyethylene as a hard segment, and an ethylene / propylene / diene ternary copolymer Polyolefin-based thermoplastic elastomer consisting of a blended body with a soft segment, mainly polybutylene terephthalate as a hard segment,
Polyester thermoplastic elastomer mainly composed of block copolymer having polytetramethylene ether glycol or aliphatic polyester as a soft segment, vinylidene fluoride / hexafluoropropylene copolymer or tetrafluoroethylene / propylene copolymer Fluorine-based thermoplastic elastomer, polyamide-based thermoplastic elastomer such as polyesteramide or polyetheramide, 1,2-polybutadiene-based thermoplastic elastomer, vinyl chloride-based thermoplastic elastomer,
Ethylene / vinyl acetate thermoplastic elastomer, chlorinated polyethylene thermoplastic elastomer, ethylene and α,
Examples thereof include ionomer-based thermoplastic elastomers obtained by neutralizing a copolymer of β-ethylenically unsaturated carboxylic acid or its alkyl ester with metal ions such as Na, Ca, Zn and Mg. One or more plastic elastomers can be appropriately used. There are various types of these thermoplastic elastomers, from soft ones to fairly hard ones, but when a relatively soft thermoplastic elastomer is used, the effect of improving wear resistance, which is the object of the present invention, tends to be remarkable. Is preferable, and specifically, J
A material having a JIS-A hardness (hereinafter referred to as JIS-A hardness) of 85 or less measured according to IS K6301 can be preferably used, but a polyurethane resin is not preferable in terms of heat resistance.

Among these thermoplastic elastomers,
A polyolefin-based thermoplastic elastomer is preferable for carrying out the object of the present invention, and a polyolefin-based thermoplastic elastomer mainly composed of a blend of an ethylene / propylene / diene-based terpolymer and a polyolefin is more preferable. Is. Furthermore, JIS-
A polyolefin-based thermoplastic elastomer having an A hardness of 85 or less is more preferable. When the JIS-A hardness of the thermoplastic polyolefin-based elastomer is greater than 85, the abrasion resistance of the obtained monofilament tends to be slightly low, and the variation in thickness of the monofilament (hereinafter, referred to as wire diameter unevenness) tends to be slightly large. is there.

The content of the above-mentioned thermoplastic elastomer in the polyester monofilament is in the range of 1% by weight or more and 40% by weight or less. If the content is less than 1% by weight, the abrasion resistance is not sufficient, while if it is more than 40% by weight, the strength and elongation of the obtained monofilament is decreased and the monofilament wire diameter unevenness is increased, which is not preferable. Further, when the content of the thermoplastic elastomer in the polyester monofilament is 5% by weight or more and 30% by weight or less, the abrasion resistance and the strength / elongation property are further improved, and a uniform monofilament with less variation in wire diameter is preferable. ..

1% by weight of the thermoplastic elastomer of the present invention
As described above, the polyester monofilament containing 40% by weight or less can be obtained by the following method. The mixing of the polyester and the thermoplastic elastomer can be carried out at any stage from immediately after the completion of polycondensation of the polyester until the monofilament is spun from the spinneret, for example, in a polymerization can immediately after the completion of polycondensation,
Thermoplastic elastomer is added to the molten polyester and kneaded, chips are formed by a conventional method, dried at a temperature lower than the softening point of the thermoplastic elastomer, and then melt-spun using a melt pressure type or extruder type spinning machine. -Stretching method, or adding thermoplastic elastomer chips to dried polyester chips-After chip blending, melt spinning / stretching while kneading with an extruder type spinning machine, or a predetermined amount of polyester chips and heat with a chip quantitative feeder A method of kneading / melt-spinning / stretching with an extruder type spinning machine while supplying a thermoplastic elastomer, or melt kneading polyester and thermoplastic elastomer in advance with a uniaxial or biaxial extruder type kneading machine to form chips into thermoplastic elastomer. Dry below the softening point , And then it is a method of melt spinning and stretching are exemplified, at least once at the stage prior to melt spinning is preferably forced kneading the polyester and a thermoplastic elastomer. Further, the temperature during melt spinning may be a normal melt spinning temperature of polyester, that is, a temperature above the melting temperature of the polyester and below the decomposition temperature, but it is preferably 290 ° C. or lower in order to avoid decomposition of the thermoplastic elastomer. For the same reason, the average contact time with the molten polyester is preferably 15 minutes or less in total, and more preferably 10 minutes or less. The polyester monofilament of the present invention comprises various antioxidants, various inert particles such as titanium oxide, various polymers other than thermoplastic elastomers, various metal compounds as catalysts usually used during polyester production, and phosphorus compounds used for preventing coloration. It may be contained.

The polyester monofilament of the present invention has excellent abrasion resistance and is useful as an industrial material for papermaking nets, filters, belt cloths and the like. When used as a paper making net such as a net, it is preferable because abrasion due to calcium carbonate can be significantly suppressed.

[0012]

EXAMPLES The present invention will be described in more detail with reference to the following examples. The abrasion resistance and wire diameter unevenness in the examples were evaluated as follows.

A. Abrasion resistance evaluation method A weight of 100 g of load is attached to the tip of a polyester monofilament, and a calcium carbonate powder manufactured by Sankyo Co., Ltd. is used as a filler for neutral papermaking on a ceramic cylindrical surface having a diameter of 60 cm which rotates at 1500 rpm. A 0.5% aqueous suspension of "Escalon" (registered trademark) # 800 was contacted dropwise, and the time until the monofilament was cut was measured. The abrasion resistance when the monofilament is used as a papermaking net requires that the time required for cutting the monofilament in the present abrasion resistance evaluation is 1.3 times or more that of the conventional homopolyester monofilament. It B. Evaluation method of wire diameter unevenness Using a laser wire diameter measuring device, monofilament 250
m was measured for 5 minutes at a speed of 50 m / min, the average value of the measured values was taken as the diameter of the filament, and the difference between the maximum and minimum measured values was taken as the wire diameter unevenness. In the case where the monofilament is used as a paper making net, the difference between the maximum value and the minimum value of the measured values according to the present evaluation method is required to be 20 μm or less in view of the relation with the surface uniformity of the paper product. It is said that.

EXAMPLE 1 Intrinsic viscosity of 0.70 dried at 160 ° C. under vacuum for 8 hours (25 in a mixed solvent of phenol and tetrachloroethane 1: 1)
Polyethylene terephthalate (measured at ° C) (hereinafter PE
88 parts by weight of a chip, and a polyolefin elastomer as a thermoplastic elastomer (Mitsubishi Petrochemical Co., Ltd.)
12 parts by weight of "Thermo Run" (registered trademark) 3550, JIS A hardness 55) were mixed in a V-type blender under a nitrogen atmosphere to obtain a blend chip. Next, this blended chip is subjected to an extruder type melt spinning machine equipped with a nozzle having a hole diameter of 1.5 mm, melt-spun, cooled once, further drawn at 120 ° C. to 5.7 times, and then relaxed at 0.9 times. By setting, a polyester monofilament having a diameter of 0.22 mm, a wire diameter unevenness of 4 μm and a strength of 4.1 g / denier was obtained. When the abrasion resistance of this monofilament was evaluated, it took 120 minutes before cutting.

Comparative Example 1 A diameter of 0.22 m was obtained in the same manner as in Example 1 except that the thermoplastic polyolefin-based elastomer was not used.
m, wire diameter unevenness 2 μm, strength P 4.7 g / denier
A polyester monofilament of ET alone was obtained. When the abrasion resistance of this monofilament was evaluated, it was cut in 15 minutes.

Examples 2 and 3 98 parts by weight of PET chips and a polyolefin elastomer ("Thermo Run" (registered trademark) 3 manufactured by Mitsubishi Petrochemical Co., Ltd.)
550, JIS A hardness 55) was changed to 2 parts by weight in the same manner as in Example 1 to obtain a polyester monofilament having a diameter of 0.22 mm, a line diameter unevenness of 3 μm, and a yarn strength of 4.5 g / denier. When the abrasion resistance of this monofilament was evaluated, it took 30 minutes until cutting (Example 2). Also, 65 parts by weight of PET chips, polyolefin elastomer (“Thermo Run” manufactured by Mitsubishi Yuka Co., Ltd.)
(Registered trademark) 3550, JIS A hardness 55) was changed to 35 parts by weight in the same manner as in Example 1 with a diameter of 0.22 mm, a wire diameter unevenness of 11 μm, and a yarn strength of 3.4 g /
A denier polyester monofilament was obtained. When the abrasion resistance of this monofilament was evaluated, it took 400 minutes until cutting (Example 3).

Examples 4, 5 94 parts by weight of PET chips, polyolefin elastomer ("Thermo Run" (registered trademark) 3 manufactured by Mitsubishi Petrochemical Co., Ltd.)
550, JIS A hardness 55) was changed to 6 parts by weight in the same manner as in Example 1 to obtain a polyester monofilament having a diameter of 0.22 mm, a line diameter unevenness of 3 μm, and a yarn strength of 4.4 g / denier. When the abrasion resistance of this monofilament was evaluated, it took 70 minutes before cutting (Example 4). In addition, 72 parts by weight of PET chips, a polyolefin-based elastomer (“Thermo Run” manufactured by Mitsubishi Yuka Co., Ltd.)
(Registered trademark) 3550, JIS A hardness 55) was changed to 28 parts by weight in the same manner as in Example 1 to obtain a polyester monofilament having a diameter of 0.22 mm, a filament diameter of 8 μm and a yarn strength of 3.9 g / denier. It was The abrasion resistance of this monofilament was evaluated to be 32 before cutting.
It took 0 minutes (Example 5).

Examples 6 and 7 Polyolefin elastomers were manufactured by Mitsui Petrochemical Co., Ltd. under the trade name "MILASTOMER" (registered trademark) 8032N (J
The same as in Example 1 except that the ISA hardness was changed to 80), the diameter was 0.22 mm, the filament diameter was 5 μm, and the yarn strength was 4.
1 g / denier polyester monofilament was obtained. When the abrasion resistance of this monofilament was evaluated, it took 115 minutes before cutting (Example 6). In addition, a polyolefin-based elastomer is manufactured by Mitsui Petrochemical Industry Co., Ltd. "MILASTOMER" (registered trademark) 9020N (JIS A
In the same manner as in Example 1 except that the hardness was changed to 90), the diameter was 0.22 mm, the wire diameter unevenness was 12 μm, and the yarn strength was 4.0 g /
A denier polyester monofilament was obtained. When the abrasion resistance of this monofilament was evaluated, it took 80 minutes before cutting (Example 7).

Comparative Examples 2 and 3 For comparison, 99.5 parts by weight of a PET chip and 0 of a polyolefin-based elastomer ("Thermo Run" (registered trademark) 3550 manufactured by Mitsubishi Yuka Co., Ltd., JIS A hardness 55) were used. A polyester monofilament having a diameter of 0.22 mm, a wire diameter variation of 2 μm and a strength of 4.6 g / denier was obtained in the same manner as in Example 1 except that the amount was changed to 0.5 part by weight.
When the abrasion resistance of this monofilament was evaluated, it was 17
It was cut in minutes (Comparative Example 2). In addition, for comparison, it was carried out except that the PET chip was changed to 55 parts by weight and the polyolefin elastomer (“Thermo Run” (registered trademark) 3550 manufactured by Mitsubishi Petrochemical Co., Ltd., JIS A hardness 55) was changed to 45 parts by weight. Same as in Example 1, diameter 0.2
A 2 mm polyester monofilament was obtained. When the abrasion resistance of this monofilament was evaluated, it took 580 minutes until cutting, but the strength was low at 2.6 g / denier and the wire diameter unevenness was large at 30 μm (Comparative Example 3).

Example 8 The type of the thermoplastic elastomer is a styrene-based thermoplastic elastomer comprising a block copolymer mainly composed of polystyrene as a hard segment and mainly hydrogenated butadiene as a soft segment (“Lavalon manufactured by Mitsubishi Petrochemical Co., Ltd.”). "(Registered trademark) MJ5301C, JIS A hardness 5
A polyester monofilament having a diameter of 0.22 mm, a wire diameter unevenness of 4 μm and a yarn strength of 4.0 g / denier was obtained in the same manner as in Example 1 except for changing to 5). When the abrasion resistance of this monofilament was evaluated, it was 10 before cutting.
It took 0 minutes.

Example 9 Example 1 was repeated except that the type of the thermoplastic elastomer was changed to a polyester type thermoplastic elastomer (“Hytrel” (registered trademark) 4057, JIS A hardness 95, manufactured by Toray DuPont Co., Ltd.). Similarly diameter 0.22m
m, the filament diameter was 6 μm, and a polyester monofilament having a yarn strength of 3.9 g / denier was obtained. When the abrasion resistance of this monofilament was evaluated, it took 60 minutes before cutting.

Example 10 95 parts by weight of PET chips and the type and amount of thermoplastic elastomer were changed to fluorine-based thermoplastic elastomer ("Daiel" (registered trademark) T-530, JI manufactured by Daikin Industries, Ltd.).
A polyester monofilament having a diameter of 0.22 mm, a filament diameter of 6 μm and a yarn strength of 3.7 g / denier was obtained in the same manner as in Example 1 except that the SA hardness was 67) 5 parts by weight. When the abrasion resistance of this monofilament was evaluated, it took 50 minutes before cutting.

The above Examples 1-9 and Comparative Examples 1-
The results of No. 3 are shown in Table 1. From these results, it is found that the polyester monofilament of the present invention has excellent abrasion resistance against rubbing of the neutral papermaking filler with calcium carbonate, and the yarn strength and stable wire diameter required as a papermaking net. Recognize.

[0024]

[Table 1]

[0025]

Since the polyester monofilament of the present invention contains a specific amount of thermoplastic elastomer,
Industrial materials such as papermaking nets, filters and belt cloths that have excellent abrasion resistance against abrasion of calcium carbonate particles of neutral paper filler, necessary and sufficient thread strength and stable wire diameter. It has excellent characteristics useful as, for example,

Claims (3)

[Claims] 1. A thermoplastic elastomer containing 1% by weight or more of 4
A polyester monofilament containing 0% by weight or less. 2. The thermoplastic elastomer is a polyolefin-based thermoplastic elastomer.
The described polyester monofilament. 3. The polyester monofilament according to claim 1, wherein the thermoplastic elastomer is a polyolefin-based thermoplastic elastomer mainly composed of a blend of an ethylene / propylene / diene-based terpolymer and a polyolefin.